663666656 has 48 divisors (see below), whose sum is σ = 1435190400. Its totient is φ = 300693888.

The previous prime is 663666571. The next prime is 663666659. The reversal of 663666656 is 656666366.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (663666659) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9746 + ... + 37713.

It is an arithmetic number, because the mean of its divisors is an integer number (29899800).

Almost surely, 2^663666656 is an apocalyptic number.

It is an amenable number.

663666656 is an abundant number, since it is smaller than the sum of its proper divisors (771523744).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

663666656 is a wasteful number, since it uses less digits than its factorization.

663666656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47511 (or 47503 counting only the distinct ones).

The product of its digits is 4199040, while the sum is 50.

The square root of 663666656 is about 25761.7285134364. The cubic root of 663666656 is about 872.2681188813.

The spelling of 663666656 in words is "six hundred sixty-three million, six hundred sixty-six thousand, six hundred fifty-six".