21965164 has 12 divisors (see below), whose sum is σ = 41395984. Its totient is φ = 10137744.

The previous prime is 21965149. The next prime is 21965219. The reversal of 21965164 is 46156912.

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, 211152 + ... + 211255.

Almost surely, 2^21965164 is an apocalyptic number.

It is an amenable number.

21965164 is a deficient number, since it is larger than the sum of its proper divisors (19430820).

21965164 is a wasteful number, since it uses less digits than its factorization.

21965164 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 422424 (or 422422 counting only the distinct ones).

The product of its digits is 12960, while the sum is 34.

The square root of 21965164 is about 4686.7007585294. The cubic root of 21965164 is about 280.0559582037.

The spelling of 21965164 in words is "twenty-one million, nine hundred sixty-five thousand, one hundred sixty-four".