21987304272 has 60 divisors (see below), whose sum is σ = 61582615380. Its totient is φ = 7323300864.

The previous prime is 21987304247. The next prime is 21987304301. The reversal of 21987304272 is 27240378912.

21987304272 is a `hidden beast` number, since 2 + 198 + 7 + 30 + 427 + 2 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 17005203216 + 4982101056 = 130404^2 + 70584^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 124104 + ... + 243672.

It is an arithmetic number, because the mean of its divisors is an integer number (1026376923).

Almost surely, 2^21987304272 is an apocalyptic number.

It is an amenable number.

21987304272 is an abundant number, since it is smaller than the sum of its proper divisors (39595311108).

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

21987304272 is a wasteful number, since it uses less digits than its factorization.

21987304272 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 120860 (or 120851 counting only the distinct ones).

The product of its (nonzero) digits is 338688, while the sum is 45.

The spelling of 21987304272 in words is "twenty-one billion, nine hundred eighty-seven million, three hundred four thousand, two hundred seventy-two".