665661056500 has 48 divisors (see below), whose sum is σ = 1585967737536. Its totient is φ = 242058564000.

The previous prime is 665661056453. The next prime is 665661056513. The reversal of 665661056500 is 5650166566.

It is a congruent number.

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, 60509142 + ... + 60520141.

It is an arithmetic number, because the mean of its divisors is an integer number (33040994532).

Almost surely, 2^665661056500 is an apocalyptic number.

It is an amenable number.

665661056500 is an abundant number, since it is smaller than the sum of its proper divisors (920306681036).

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

665661056500 is a wasteful number, since it uses less digits than its factorization.

665661056500 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 121029313 (or 121029301 counting only the distinct ones).

The product of its (nonzero) digits is 972000, while the sum is 46.

The spelling of 665661056500 in words is "six hundred sixty-five billion, six hundred sixty-one million, fifty-six thousand, five hundred".