21368972 has 12 divisors (see below), whose sum is σ = 37449720. Its totient is φ = 10669056.

The previous prime is 21368953. The next prime is 21368987. The reversal of 21368972 is 27986312.

It is a super-3 number, since 3×21368972³ (a number of 23 digits) contains 333 as substring.

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, 398 + ... + 6549.

It is an arithmetic number, because the mean of its divisors is an integer number (3120810).

Almost surely, 2^21368972 is an apocalyptic number.

It is an amenable number.

21368972 is a deficient number, since it is larger than the sum of its proper divisors (16080748).

21368972 is a wasteful number, since it uses less digits than its factorization.

21368972 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7720 (or 7718 counting only the distinct ones).

The product of its digits is 36288, while the sum is 38.

The square root of 21368972 is about 4622.6585424407. The cubic root of 21368972 is about 277.4988642650.

The spelling of 21368972 in words is "twenty-one million, three hundred sixty-eight thousand, nine hundred seventy-two".