21731432 has 16 divisors (see below), whose sum is σ = 41848260. Its totient is φ = 10571904.

The previous prime is 21731419. The next prime is 21731441. The reversal of 21731432 is 23413712.

It can be written as a sum of positive squares in 2 ways, for example, as 18541636 + 3189796 = 4306^2 + 1786^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21731398 and 21731407.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 36413 + ... + 37004.

Almost surely, 2^21731432 is an apocalyptic number.

It is an amenable number.

21731432 is a deficient number, since it is larger than the sum of its proper divisors (20116828).

21731432 is a wasteful number, since it uses less digits than its factorization.

21731432 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 73460 (or 73456 counting only the distinct ones).

The product of its digits is 1008, while the sum is 23.

The square root of 21731432 is about 4661.6984029429. The cubic root of 21731432 is about 279.0590523461.

The spelling of 21731432 in words is "twenty-one million, seven hundred thirty-one thousand, four hundred thirty-two".