21665032 has 16 divisors (see below), whose sum is σ = 41932800. Its totient is φ = 10482960.

The previous prime is 21665009. The next prime is 21665041. The reversal of 21665032 is 23056612.

It is a super-2 number, since 2×21665032² = 938747223122048, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21664988 and 21665006.

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, 43432 + ... + 43927.

It is an arithmetic number, because the mean of its divisors is an integer number (2620800).

Almost surely, 2^21665032 is an apocalyptic number.

It is an amenable number.

21665032 is a deficient number, since it is larger than the sum of its proper divisors (20267768).

21665032 is a wasteful number, since it uses less digits than its factorization.

21665032 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 87396 (or 87392 counting only the distinct ones).

The product of its (nonzero) digits is 2160, while the sum is 25.

The square root of 21665032 is about 4654.5710865772. The cubic root of 21665032 is about 278.7745424040.

The spelling of 21665032 in words is "twenty-one million, six hundred sixty-five thousand, thirty-two".