Why 1 and 2 are not friends with 4 and 7?
Many people think that something happens in life because they want it. In fact, everything happens as it is determined by ones karma. The karma is recorded in human consciousness and is held by grahas or planets. This means that everything that happens in human life is a reflection of his karma.
Every single number that is used in numerology is related to appropriate planet. This means that we can express anything in numbers. For numbers, we know the meaning through the planets that manage them.
In numerology, 1 means the Sun (Surya, Ravi), but 2 means the Moon (Chandra). Sun in the moon are the best friends. Both of these have a mutually beneficial relationship. This means that people who have a soul (jiva) number 1 and 2 will be in good relationships. Of course, you should always look at other factors that can be done by a professional numerologist or astrologer, but in general, it will be as said before.
Since ancient times people have known sun and moon eclipses. Eclipses are considered to be a karmic disadvantage. It is usually advised to avoid them. Usually, people are doing exactly the opposite, gathering together and gladly watching the current solar eclipse. This is because people are not aware of the true meaning and nature of eclipses.
We remember well the August 21, 2017 solar eclipse, which peaked above the United States. All news sites showed how Donald Trump and his family were watching the eclipse of the sun. Shortly after that September 20, 2017, the hurricane Maria almost completely ruined Puerto Rico. Why it happened? It has a karmic reasons. The President represents not only himself as a private individual, but also the state as a whole. Consequently, there were visible consequences for both the US and President Trump's private property in Florida.
Solar eclipses in the vedic tradition are considered to be the shadowy planets of Rahu and Ketu's visual manifestations. Rahu in numerology is 4, Ketu in numerology is 7.
In the Vedic tradition, everything is based on myths or puranas. There is widespread purana on the asurah (demon) of Svarphanu, who ate the sun and the moon. Afterwards, Vishnu, with his sudarshana chakra, cut Svarphanu in half to release the sun and the moon. This was the birth of Rahu and Ketu - the shadow planets. From the point of view of the puranas, the eclipse is when Rahu or Ketu are trying to eat the Sun or the Moon. The Sun rules the human ego (Ahankara), but the moon rules the human mind (manas). During the time of eclipse, man is left alone with himself without divine protection. This is the time when mantras should be chanted to protect yourself from negative influences of malefic planets.
As you have come to understand, in numerology, people's relationships are determined by numbers (planets) rather than human desires. Rahu and Ketu are the greatest enemies of the Sun and Moon. This means that if your jiva number or karma number are 1 or 2 and your partner is 4 or 7, then your life will be a real test for both of you. You both will give each other a karmic lesson during cohabitation.