21315042252 has 72 divisors (see below), whose sum is σ = 61596883712. Its totient is φ = 6088024800.

The previous prime is 21315042233. The next prime is 21315042263. The reversal of 21315042252 is 25224051312.

21315042252 is a `hidden beast` number, since 2 + 131 + 504 + 2 + 25 + 2 = 666.

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, 872727 + ... + 896817.

Almost surely, 2^21315042252 is an apocalyptic number.

It is an amenable number.

21315042252 is an abundant number, since it is smaller than the sum of its proper divisors (40281841460).

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

21315042252 is a wasteful number, since it uses less digits than its factorization.

21315042252 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27619 (or 27614 counting only the distinct ones).

The product of its (nonzero) digits is 4800, while the sum is 27.

Adding to 21315042252 its reverse (25224051312), we get a palindrome (46539093564).

The spelling of 21315042252 in words is "twenty-one billion, three hundred fifteen million, forty-two thousand, two hundred fifty-two".