21902265 has 128 divisors (see below), whose sum is σ = 50688000. Its totient is φ = 8890560.

The previous prime is 21902227. The next prime is 21902291. The reversal of 21902265 is 56220912.

It is not a de Polignac number, because 21902265 - 2⁶ = 21902201 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 509334 + ... + 509376.

It is an arithmetic number, because the mean of its divisors is an integer number (396000).

Almost surely, 2^21902265 is an apocalyptic number.

It is an amenable number.

21902265 is an abundant number, since it is smaller than the sum of its proper divisors (28785735).

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

21902265 is a wasteful number, since it uses less digits than its factorization.

21902265 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 89 (or 69 counting only the distinct ones).

The product of its (nonzero) digits is 2160, while the sum is 27.

The square root of 21902265 is about 4679.9855769009. The cubic root of 21902265 is about 279.7883817703.

The spelling of 21902265 in words is "twenty-one million, nine hundred two thousand, two hundred sixty-five".