21330538572 has 24 divisors (see below), whose sum is σ = 56881436416. Its totient is φ = 6094439568.

The previous prime is 21330538553. The next prime is 21330538601. The reversal of 21330538572 is 27583503312.

It is a self number, because there is not a number n which added to its sum of digits gives 21330538572.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 126967408 + ... + 126967575.

Almost surely, 2^21330538572 is an apocalyptic number.

It is an amenable number.

21330538572 is an abundant number, since it is smaller than the sum of its proper divisors (35550897844).

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

21330538572 is a wasteful number, since it uses less digits than its factorization.

21330538572 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 253934997 (or 253934995 counting only the distinct ones).

The product of its (nonzero) digits is 151200, while the sum is 39.

The spelling of 21330538572 in words is "twenty-one billion, three hundred thirty million, five hundred thirty-eight thousand, five hundred seventy-two".