21564914 has 24 divisors (see below), whose sum is σ = 37585344. Its totient is φ = 9090000.

The previous prime is 21564793. The next prime is 21564929. The reversal of 21564914 is 41946512.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 142739 + ... + 142889.

It is an arithmetic number, because the mean of its divisors is an integer number (1566056).

Almost surely, 2^21564914 is an apocalyptic number.

21564914 is a deficient number, since it is larger than the sum of its proper divisors (16020430).

21564914 is a wasteful number, since it uses less digits than its factorization.

21564914 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 362 (or 261 counting only the distinct ones).

The product of its digits is 8640, while the sum is 32.

The square root of 21564914 is about 4643.8038287594. The cubic root of 21564914 is about 278.3444568285.

The spelling of 21564914 in words is "twenty-one million, five hundred sixty-four thousand, nine hundred fourteen".