621438864 has 40 divisors (see below), whose sum is σ = 1613557440. Its totient is φ = 206091648.

The previous prime is 621438827. The next prime is 621438887. The reversal of 621438864 is 468834126.

It is a super-2 number, since 2×621438864² = 772372523379220992, which contains 22 as substring.

It is a nude number because it is divisible by every one of its digits.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 23404 + ... + 42315.

It is an arithmetic number, because the mean of its divisors is an integer number (40338936).

Almost surely, 2^621438864 is an apocalyptic number.

It is an amenable number.

621438864 is an abundant number, since it is smaller than the sum of its proper divisors (992118576).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

621438864 is a wasteful number, since it uses less digits than its factorization.

621438864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 65927 (or 65921 counting only the distinct ones).

The product of its digits is 221184, while the sum is 42.

The square root of 621438864 is about 24928.6755364179. The cubic root of 621438864 is about 853.3610242208.

The spelling of 621438864 in words is "six hundred twenty-one million, four hundred thirty-eight thousand, eight hundred sixty-four".