661554756 has 48 divisors (see below), whose sum is σ = 1770478080. Its totient is φ = 213403680.

The previous prime is 661554743. The next prime is 661554763. The reversal of 661554756 is 657455166.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 95451 + ... + 102146.

It is an arithmetic number, because the mean of its divisors is an integer number (36884960).

Almost surely, 2^661554756 is an apocalyptic number.

It is an amenable number.

661554756 is an abundant number, since it is smaller than the sum of its proper divisors (1108923324).

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

661554756 is a wasteful number, since it uses less digits than its factorization.

661554756 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 197641 (or 197633 counting only the distinct ones).

The product of its digits is 756000, while the sum is 45.

The square root of 661554756 is about 25720.7067554529. The cubic root of 661554756 is about 871.3419006314.

The spelling of 661554756 in words is "six hundred sixty-one million, five hundred fifty-four thousand, seven hundred fifty-six".