621921904 has 10 divisors (see below), whose sum is σ = 1204973720. Its totient is φ = 310960944.

The previous prime is 621921877. The next prime is 621921947. The reversal of 621921904 is 409129126.

It is a self number, because there is not a number n which added to its sum of digits gives 621921904.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19435044 + ... + 19435075.

It is an arithmetic number, because the mean of its divisors is an integer number (120497372).

Almost surely, 2^621921904 is an apocalyptic number.

It is an amenable number.

621921904 is a deficient number, since it is larger than the sum of its proper divisors (583051816).

621921904 is a wasteful number, since it uses less digits than its factorization.

621921904 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38870127 (or 38870121 counting only the distinct ones).

The product of its (nonzero) digits is 7776, while the sum is 34.

The square root of 621921904 is about 24938.3620953743. The cubic root of 621921904 is about 853.5820707721.

The spelling of 621921904 in words is "six hundred twenty-one million, nine hundred twenty-one thousand, nine hundred four".