21207374856 has 64 divisors (see below), whose sum is σ = 62009880000. Its totient is φ = 6697064448.

The previous prime is 21207374849. The next prime is 21207374873. The reversal of 21207374856 is 65847370212.

21207374856 is a `hidden beast` number, since 21 + 207 + 374 + 8 + 56 = 666.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2579641 + ... + 2587848.

It is an arithmetic number, because the mean of its divisors is an integer number (968904375).

Almost surely, 2^21207374856 is an apocalyptic number.

It is an amenable number.

21207374856 is an abundant number, since it is smaller than the sum of its proper divisors (40802505144).

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

21207374856 is a wasteful number, since it uses less digits than its factorization.

21207374856 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5167523 (or 5167513 counting only the distinct ones).

The product of its (nonzero) digits is 564480, while the sum is 45.

The spelling of 21207374856 in words is "twenty-one billion, two hundred seven million, three hundred seventy-four thousand, eight hundred fifty-six".