21507199056 has 120 divisors (see below), whose sum is σ = 71336725824. Its totient is φ = 6144906240.

The previous prime is 21507199039. The next prime is 21507199079. The reversal of 21507199056 is 65099170512.

21507199056 is a `hidden beast` number, since 2 + 1 + 507 + 1 + 9 + 90 + 56 = 666.

It is a super-2 number, since 2×21507199056² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 367905 + ... + 422336.

Almost surely, 2^21507199056 is an apocalyptic number.

It is an amenable number.

21507199056 is an abundant number, since it is smaller than the sum of its proper divisors (49829526768).

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

21507199056 is an equidigital number, since it uses as much as digits as its factorization.

21507199056 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 790271 (or 790253 counting only the distinct ones).

The product of its (nonzero) digits is 170100, while the sum is 45.

The spelling of 21507199056 in words is "twenty-one billion, five hundred seven million, one hundred ninety-nine thousand, fifty-six".