21902465 has 8 divisors (see below), whose sum is σ = 28304808. Its totient is φ = 16174080.

The previous prime is 21902431. The next prime is 21902471. The reversal of 21902465 is 56420912.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 65536 + 21836929 = 256^2 + 4673^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a de Polignac number, because none of the positive numbers 2^k-21902465 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 168416 + ... + 168545.

It is an arithmetic number, because the mean of its divisors is an integer number (3538101).

Almost surely, 2^21902465 is an apocalyptic number.

It is an amenable number.

21902465 is a deficient number, since it is larger than the sum of its proper divisors (6402343).

21902465 is a wasteful number, since it uses less digits than its factorization.

21902465 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 336979.

The product of its (nonzero) digits is 4320, while the sum is 29.

The square root of 21902465 is about 4680.0069444393. The cubic root of 21902465 is about 279.7892333946.

The spelling of 21902465 in words is "twenty-one million, nine hundred two thousand, four hundred sixty-five".