665625561165 has 24 divisors (see below), whose sum is σ = 1153770322848. Its totient is φ = 354994345440.

The previous prime is 665625561163. The next prime is 665625561173. The reversal of 665625561165 is 561165526566.

665625561165 is a `hidden beast` number, since 6 + 6 + 5 + 62 + 5 + 561 + 16 + 5 = 666.

It is not a de Polignac number, because 665625561165 - 2¹ = 665625561163 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (665625561163) 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 23 ways as a sum of consecutive naturals, for example, 4410810 + ... + 4559220.

It is an arithmetic number, because the mean of its divisors is an integer number (48073763452).

Almost surely, 2^665625561165 is an apocalyptic number.

It is an amenable number.

665625561165 is a deficient number, since it is larger than the sum of its proper divisors (488144761683).

665625561165 is a wasteful number, since it uses less digits than its factorization.

665625561165 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 248089 (or 248086 counting only the distinct ones).

The product of its digits is 9720000, while the sum is 54.

The spelling of 665625561165 in words is "six hundred sixty-five billion, six hundred twenty-five million, five hundred sixty-one thousand, one hundred sixty-five".