621616656 has 40 divisors (see below), whose sum is σ = 1607307840. Its totient is φ = 207016576.

The previous prime is 621616649. The next prime is 621616663. The reversal of 621616656 is 656616126.

It is an interprime number because it is at equal distance from previous prime (621616649) and next prime (621616663).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 53410 + ... + 63998.

It is an arithmetic number, because the mean of its divisors is an integer number (40182696).

Almost surely, 2^621616656 is an apocalyptic number.

It is an amenable number.

621616656 is an abundant number, since it is smaller than the sum of its proper divisors (985691184).

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

621616656 is a wasteful number, since it uses less digits than its factorization.

621616656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11823 (or 11817 counting only the distinct ones).

The product of its digits is 77760, while the sum is 39.

The square root of 621616656 is about 24932.2412951584. The cubic root of 621616656 is about 853.4423978980.

The spelling of 621616656 in words is "six hundred twenty-one million, six hundred sixteen thousand, six hundred fifty-six".