21173448664 has 16 divisors (see below), whose sum is σ = 39701914920. Its totient is φ = 10586271360.

The previous prime is 21173448641. The next prime is 21173448683. The reversal of 21173448664 is 46684437112.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 223632 + ... + 303904.

Almost surely, 2^21173448664 is an apocalyptic number.

It is an amenable number.

21173448664 is a deficient number, since it is larger than the sum of its proper divisors (18528466256).

21173448664 is a wasteful number, since it uses less digits than its factorization.

21173448664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 113250 (or 113246 counting only the distinct ones).

The product of its digits is 774144, while the sum is 46.

The spelling of 21173448664 in words is "twenty-one billion, one hundred seventy-three million, four hundred forty-eight thousand, six hundred sixty-four".