21902444 has 12 divisors (see below), whose sum is σ = 38390184. Its totient is φ = 10933824.

The previous prime is 21902431. The next prime is 21902471. The reversal of 21902444 is 44420912.

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, 1277 + ... + 6740.

It is an arithmetic number, because the mean of its divisors is an integer number (3199182).

Almost surely, 2^21902444 is an apocalyptic number.

It is an amenable number.

21902444 is a deficient number, since it is larger than the sum of its proper divisors (16487740).

21902444 is a wasteful number, since it uses less digits than its factorization.

21902444 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8704 (or 8702 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 26.

The square root of 21902444 is about 4680.0047008523. The cubic root of 21902444 is about 279.7891439743.

The spelling of 21902444 in words is "twenty-one million, nine hundred two thousand, four hundred forty-four".