21038664492 has 24 divisors (see below), whose sum is σ = 54544686000. Its totient is φ = 7012888128.

The previous prime is 21038664467. The next prime is 21038664523. The reversal of 21038664492 is 29446683012.

21038664492 is a `hidden beast` number, since 21 + 0 + 3 + 86 + 64 + 492 = 666.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 97401117 + ... + 97401332.

It is an arithmetic number, because the mean of its divisors is an integer number (2272695250).

Almost surely, 2^21038664492 is an apocalyptic number.

It is an amenable number.

21038664492 is an abundant number, since it is smaller than the sum of its proper divisors (33506021508).

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

21038664492 is a wasteful number, since it uses less digits than its factorization.

21038664492 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 194802462 (or 194802454 counting only the distinct ones).

The product of its (nonzero) digits is 497664, while the sum is 45.

The spelling of 21038664492 in words is "twenty-one billion, thirty-eight million, six hundred sixty-four thousand, four hundred ninety-two".