21372973572 has 24 divisors (see below), whose sum is σ = 49900414816. Its totient is φ = 7120018368.

The previous prime is 21372973553. The next prime is 21372973577. The reversal of 21372973572 is 27537927312.

It is not an unprimeable number, because it can be changed into a prime (21372973577) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 517558 + ... + 557325.

Almost surely, 2^21372973572 is an apocalyptic number.

It is an amenable number.

21372973572 is an abundant number, since it is smaller than the sum of its proper divisors (28527441244).

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

21372973572 is a wasteful number, since it uses less digits than its factorization.

21372973572 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1076547 (or 1076545 counting only the distinct ones).

The product of its digits is 1111320, while the sum is 48.

The spelling of 21372973572 in words is "twenty-one billion, three hundred seventy-two million, nine hundred seventy-three thousand, five hundred seventy-two".