21866252 has 12 divisors (see below), whose sum is σ = 38750880. Its totient is φ = 10794576.

The previous prime is 21866249. The next prime is 21866303. The reversal of 21866252 is 25266812.

It is a super-4 number, since 4×21866252⁴ (a number of 30 digits) contains 4444 as substring.

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, 34283 + ... + 34914.

It is an arithmetic number, because the mean of its divisors is an integer number (3229240).

Almost surely, 2^21866252 is an apocalyptic number.

It is an amenable number.

21866252 is a deficient number, since it is larger than the sum of its proper divisors (16884628).

21866252 is a wasteful number, since it uses less digits than its factorization.

21866252 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 69280 (or 69278 counting only the distinct ones).

The product of its digits is 11520, while the sum is 32.

The square root of 21866252 is about 4676.1364394123. The cubic root of 21866252 is about 279.6349494415.

The spelling of 21866252 in words is "twenty-one million, eight hundred sixty-six thousand, two hundred fifty-two".