21896564 has 12 divisors (see below), whose sum is σ = 38691744. Its totient is φ = 10841784.

The previous prime is 21896543. The next prime is 21896597. The reversal of 21896564 is 46569812.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 26162 + ... + 26985.

It is an arithmetic number, because the mean of its divisors is an integer number (3224312).

Almost surely, 2^21896564 is an apocalyptic number.

It is an amenable number.

21896564 is a deficient number, since it is larger than the sum of its proper divisors (16795180).

21896564 is a wasteful number, since it uses less digits than its factorization.

21896564 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 53254 (or 53252 counting only the distinct ones).

The product of its digits is 103680, while the sum is 41.

The square root of 21896564 is about 4679.3764541870. The cubic root of 21896564 is about 279.7641040380.

The spelling of 21896564 in words is "twenty-one million, eight hundred ninety-six thousand, five hundred sixty-four".