20980664 has 8 divisors (see below), whose sum is σ = 39338760. Its totient is φ = 10490328.

The previous prime is 20980651. The next prime is 20980681. The reversal of 20980664 is 46608902.

It is a tau number, because it is divible by the number of its divisors (8).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1311284 + ... + 1311299.

It is an arithmetic number, because the mean of its divisors is an integer number (4917345).

Almost surely, 2^20980664 is an apocalyptic number.

It is an amenable number.

20980664 is a deficient number, since it is larger than the sum of its proper divisors (18358096).

20980664 is a wasteful number, since it uses less digits than its factorization.

20980664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2622589 (or 2622585 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 35.

The square root of 20980664 is about 4580.4654785294. The cubic root of 20980664 is about 275.8077145597.

The spelling of 20980664 in words is "twenty million, nine hundred eighty thousand, six hundred sixty-four".