665560617172 has 24 divisors (see below), whose sum is σ = 1282272757920. Its totient is φ = 299752068960.

The previous prime is 665560617143. The next prime is 665560617179. The reversal of 665560617172 is 271716065566.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (665560617179) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 69382258 + ... + 69391849.

It is an arithmetic number, because the mean of its divisors is an integer number (53428031580).

Almost surely, 2^665560617172 is an apocalyptic number.

It is an amenable number.

665560617172 is a deficient number, since it is larger than the sum of its proper divisors (616712140748).

665560617172 is a wasteful number, since it uses less digits than its factorization.

665560617172 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 138774231 (or 138774229 counting only the distinct ones).

The product of its (nonzero) digits is 3175200, while the sum is 52.

The spelling of 665560617172 in words is "six hundred sixty-five billion, five hundred sixty million, six hundred seventeen thousand, one hundred seventy-two".