665243634564 has 48 divisors (see below), whose sum is σ = 1725104606400. Its totient is φ = 221696592768.

The previous prime is 665243634547. The next prime is 665243634581. The reversal of 665243634564 is 465436342566.

665243634564 is a `hidden beast` number, since 6 + 6 + 5 + 2 + 43 + 6 + 34 + 564 = 666.

It is an interprime number because it is at equal distance from previous prime (665243634547) and next prime (665243634581).

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a self number, because there is not a number n which added to its sum of digits gives 665243634564.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 241734 + ... + 1178525.

It is an arithmetic number, because the mean of its divisors is an integer number (35939679300).

Almost surely, 2^665243634564 is an apocalyptic number.

It is an amenable number.

665243634564 is an abundant number, since it is smaller than the sum of its proper divisors (1059860971836).

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

665243634564 is a wasteful number, since it uses less digits than its factorization.

665243634564 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1424609 (or 1424601 counting only the distinct ones).

The product of its digits is 37324800, while the sum is 54.

The spelling of 665243634564 in words is "six hundred sixty-five billion, two hundred forty-three million, six hundred thirty-four thousand, five hundred sixty-four".