21512984 has 16 divisors (see below), whose sum is σ = 41427600. Its totient is φ = 10465632.

The previous prime is 21512969. The next prime is 21513001. The reversal of 21512984 is 48921512.

It is a self number, because there is not a number n which added to its sum of digits gives 21512984.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 36044 + ... + 36635.

It is an arithmetic number, because the mean of its divisors is an integer number (2589225).

Almost surely, 2^21512984 is an apocalyptic number.

It is an amenable number.

21512984 is a deficient number, since it is larger than the sum of its proper divisors (19914616).

21512984 is a wasteful number, since it uses less digits than its factorization.

21512984 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 72722 (or 72718 counting only the distinct ones).

The product of its digits is 5760, while the sum is 32.

The square root of 21512984 is about 4638.2091371563. The cubic root of 21512984 is about 278.1208521706.

The spelling of 21512984 in words is "twenty-one million, five hundred twelve thousand, nine hundred eighty-four".