21715432 has 16 divisors (see below), whose sum is σ = 42120900. Its totient is φ = 10483200.

The previous prime is 21715361. The next prime is 21715433. The reversal of 21715432 is 23451712.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 19483396 + 2232036 = 4414^2 + 1494^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21715397 and 21715406.

It is not an unprimeable number, because it can be changed into a prime (21715433) 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, 46569 + ... + 47032.

Almost surely, 2^21715432 is an apocalyptic number.

It is an amenable number.

21715432 is a deficient number, since it is larger than the sum of its proper divisors (20405468).

21715432 is a wasteful number, since it uses less digits than its factorization.

21715432 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 93636 (or 93632 counting only the distinct ones).

The product of its digits is 1680, while the sum is 25.

The square root of 21715432 is about 4659.9819742141. The cubic root of 21715432 is about 278.9905487906.

The spelling of 21715432 in words is "twenty-one million, seven hundred fifteen thousand, four hundred thirty-two".