665947169388 has 72 divisors (see below), whose sum is σ = 1756690816608. Its totient is φ = 212314722048.

The previous prime is 665947169357. The next prime is 665947169389. The reversal of 665947169388 is 883961749566.

665947169388 is a `hidden beast` number, since 6 + 65 + 9 + 471 + 6 + 93 + 8 + 8 = 666.

It is a Smith number, since the sum of its digits (72) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (665947169389) by changing a digit.

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 23 ways as a sum of consecutive naturals, for example, 15539206 + ... + 15582002.

It is an arithmetic number, because the mean of its divisors is an integer number (24398483564).

Almost surely, 2^665947169388 is an apocalyptic number.

It is an amenable number.

665947169388 is an abundant number, since it is smaller than the sum of its proper divisors (1090743647220).

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

665947169388 is a wasteful number, since it uses less digits than its factorization.

665947169388 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 61623 (or 61618 counting only the distinct ones).

The product of its digits is 470292480, while the sum is 72.

The spelling of 665947169388 in words is "six hundred sixty-five billion, nine hundred forty-seven million, one hundred sixty-nine thousand, three hundred eighty-eight".