21639596 has 24 divisors (see below), whose sum is σ = 43110144. Its totient is φ = 9408080.

The previous prime is 21639587. The next prime is 21639647. The reversal of 21639596 is 69593612.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9680 + ... + 11703.

It is an arithmetic number, because the mean of its divisors is an integer number (1796256).

Almost surely, 2^21639596 is an apocalyptic number.

It is an amenable number.

21639596 is a deficient number, since it is larger than the sum of its proper divisors (21470548).

21639596 is a wasteful number, since it uses less digits than its factorization.

21639596 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21421 (or 21419 counting only the distinct ones).

The product of its digits is 87480, while the sum is 41.

The square root of 21639596 is about 4651.8379163509. The cubic root of 21639596 is about 278.6654005371.

The spelling of 21639596 in words is "twenty-one million, six hundred thirty-nine thousand, five hundred ninety-six".