21931732 has 12 divisors (see below), whose sum is σ = 38416000. Its totient is φ = 10955736.

The previous prime is 21931727. The next prime is 21931733. The reversal of 21931732 is 23713912.

It is a self number, because there is not a number n which added to its sum of digits gives 21931732.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21931733) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4519 + ... + 8017.

Almost surely, 2^21931732 is an apocalyptic number.

It is an amenable number.

21931732 is a deficient number, since it is larger than the sum of its proper divisors (16484268).

21931732 is a wasteful number, since it uses less digits than its factorization.

21931732 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5070 (or 5068 counting only the distinct ones).

The product of its digits is 2268, while the sum is 28.

The square root of 21931732 is about 4683.1327121917. The cubic root of 21931732 is about 279.9137999960.

The spelling of 21931732 in words is "twenty-one million, nine hundred thirty-one thousand, seven hundred thirty-two".