21731464 has 16 divisors (see below), whose sum is σ = 40956300. Its totient is φ = 10809792.

The previous prime is 21731453. The next prime is 21731473. The reversal of 21731464 is 46413712.

It can be written as a sum of positive squares in 2 ways, for example, as 14212900 + 7518564 = 3770^2 + 2742^2 .

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, 5319 + ... + 8470.

Almost surely, 2^21731464 is an apocalyptic number.

It is an amenable number.

21731464 is a deficient number, since it is larger than the sum of its proper divisors (19224836).

21731464 is a wasteful number, since it uses less digits than its factorization.

21731464 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13992 (or 13988 counting only the distinct ones).

The product of its digits is 4032, while the sum is 28.

The square root of 21731464 is about 4661.7018351671. The cubic root of 21731464 is about 279.0591893195.

The spelling of 21731464 in words is "twenty-one million, seven hundred thirty-one thousand, four hundred sixty-four".