21565052 has 6 divisors (see below), whose sum is σ = 37738848. Its totient is φ = 10782524.

The previous prime is 21564989. The next prime is 21565073. The reversal of 21565052 is 25056512.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2695628 + ... + 2695635.

It is an arithmetic number, because the mean of its divisors is an integer number (6289808).

Almost surely, 2^21565052 is an apocalyptic number.

It is an amenable number.

21565052 is a deficient number, since it is larger than the sum of its proper divisors (16173796).

21565052 is a wasteful number, since it uses less digits than its factorization.

21565052 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5391267 (or 5391265 counting only the distinct ones).

The product of its (nonzero) digits is 3000, while the sum is 26.

The square root of 21565052 is about 4643.8186872444. The cubic root of 21565052 is about 278.3450505623.

The spelling of 21565052 in words is "twenty-one million, five hundred sixty-five thousand, fifty-two".