21639392 has 24 divisors (see below), whose sum is σ = 43242696. Its totient is φ = 10657152.

The previous prime is 21639383. The next prime is 21639427. The reversal of 21639392 is 29393612.

It is a super-2 number, since 2×21639392² = 936526572259328, which contains 22 as substring.

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, 2903 + ... + 7190.

It is an arithmetic number, because the mean of its divisors is an integer number (1801779).

Almost surely, 2^21639392 is an apocalyptic number.

It is an amenable number.

21639392 is a deficient number, since it is larger than the sum of its proper divisors (21603304).

21639392 is a wasteful number, since it uses less digits than its factorization.

21639392 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10170 (or 10162 counting only the distinct ones).

The product of its digits is 17496, while the sum is 35.

The square root of 21639392 is about 4651.8159894820. The cubic root of 21639392 is about 278.6645248596.

The spelling of 21639392 in words is "twenty-one million, six hundred thirty-nine thousand, three hundred ninety-two".