21069872 has 20 divisors (see below), whose sum is σ = 41927376. Its totient is φ = 10249920.

The previous prime is 21069857. The next prime is 21069901. The reversal of 21069872 is 27896012.

It is a happy number.

It is a hoax number, since the sum of its digits (35) coincides with the sum of the digits of its distinct prime factors.

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, 17204 + ... + 18387.

Almost surely, 2^21069872 is an apocalyptic number.

It is an amenable number.

21069872 is a deficient number, since it is larger than the sum of its proper divisors (20857504).

21069872 is a wasteful number, since it uses less digits than its factorization.

21069872 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35636 (or 35630 counting only the distinct ones).

The product of its (nonzero) digits is 12096, while the sum is 35.

The square root of 21069872 is about 4590.1930242638. The cubic root of 21069872 is about 276.1980654880.

The spelling of 21069872 in words is "twenty-one million, sixty-nine thousand, eight hundred seventy-two".