21256030425664 has 28 divisors (see below), whose sum is σ = 44399931977200. Its totient is φ = 10068645990528.

The previous prime is 21256030425647. The next prime is 21256030425671. The reversal of 21256030425664 is 46652403065212.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8740142874 + ... + 8740145305.

Almost surely, 2^{21256030425664} is an apocalyptic number.

It is an amenable number.

21256030425664 is an abundant number, since it is smaller than the sum of its proper divisors (23143901551536).

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

21256030425664 is a wasteful number, since it uses less digits than its factorization.

21256030425664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17480288210 (or 17480288200 counting only the distinct ones).

The product of its (nonzero) digits is 2073600, while the sum is 46.

The spelling of 21256030425664 in words is "twenty-one trillion, two hundred fifty-six billion, thirty million, four hundred twenty-five thousand, six hundred sixty-four".