663971628 has 24 divisors (see below), whose sum is σ = 1550503360. Its totient is φ = 221147280.

The previous prime is 663971611. The next prime is 663971657. The reversal of 663971628 is 826179366.

It is a Smith number, since the sum of its digits (48) coincides with the sum of the digits of its prime factors.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5938 + ... + 36921.

Almost surely, 2^663971628 is an apocalyptic number.

It is an amenable number.

663971628 is an abundant number, since it is smaller than the sum of its proper divisors (886531732).

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

663971628 is a wasteful number, since it uses less digits than its factorization.

663971628 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 44157 (or 44155 counting only the distinct ones).

The product of its digits is 653184, while the sum is 48.

The square root of 663971628 is about 25767.6469240014. The cubic root of 663971628 is about 872.4017083440.

The spelling of 663971628 in words is "six hundred sixty-three million, nine hundred seventy-one thousand, six hundred twenty-eight".