21917232 has 30 divisors (see below), whose sum is σ = 61338212. Its totient is φ = 7305696.

The previous prime is 21917227. The next prime is 21917281. The reversal of 21917232 is 23271912.

It is a Smith number, since the sum of its digits (27) coincides with the sum of the digits of its prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 21917196 and 21917205.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 75958 + ... + 76245.

Almost surely, 2^21917232 is an apocalyptic number.

It is an amenable number.

21917232 is an abundant number, since it is smaller than the sum of its proper divisors (39420980).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21917232 is a wasteful number, since it uses less digits than its factorization.

21917232 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 152217 (or 152208 counting only the distinct ones).

The product of its digits is 1512, while the sum is 27.

The square root of 21917232 is about 4681.5843472055. The cubic root of 21917232 is about 279.8520987603.

The spelling of 21917232 in words is "twenty-one million, nine hundred seventeen thousand, two hundred thirty-two".