1620978926 has 16 divisors (see below), whose sum is σ = 2782905984. Its totient is φ = 693684024.

The previous prime is 1620978913. The next prime is 1620978929. The reversal of 1620978926 is 6298790261.

It is a happy number.

It is a super-2 number, since 2×1620978926² = 5255145357072226952, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1620978929) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 75200 + ... + 94323.

It is an arithmetic number, because the mean of its divisors is an integer number (173931624).

Almost surely, 2^1620978926 is an apocalyptic number.

1620978926 is a deficient number, since it is larger than the sum of its proper divisors (1161927058).

1620978926 is a wasteful number, since it uses less digits than its factorization.

1620978926 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 170215.

The product of its (nonzero) digits is 653184, while the sum is 50.

The square root of 1620978926 is about 40261.3825644376. The cubic root of 1620978926 is about 1174.6968105016.

The spelling of 1620978926 in words is "one billion, six hundred twenty million, nine hundred seventy-eight thousand, nine hundred twenty-six".