661875856 has 40 divisors (see below), whose sum is σ = 1295077824. Its totient is φ = 327680640.

The previous prime is 661875847. The next prime is 661875857. The reversal of 661875856 is 658578166.

661875856 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Smith number, since the sum of its digits (52) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (661875857) 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, 1347771 + ... + 1348261.

Almost surely, 2^661875856 is an apocalyptic number.

It is an amenable number.

661875856 is a deficient number, since it is larger than the sum of its proper divisors (633201968).

661875856 is a wasteful number, since it uses less digits than its factorization.

661875856 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1159 (or 1153 counting only the distinct ones).

The product of its digits is 2419200, while the sum is 52.

The square root of 661875856 is about 25726.9480506336. The cubic root of 661875856 is about 871.4828527480.

The spelling of 661875856 in words is "six hundred sixty-one million, eight hundred seventy-five thousand, eight hundred fifty-six".