665979874560 has 4032 divisors, whose sum is σ = 3459017834496. Its totient is φ = 118244966400.

The previous prime is 665979874519. The next prime is 665979874589. The reversal of 665979874560 is 65478979566.

665979874560 is a `hidden beast` number, since 6 + 6 + 5 + 97 + 9 + 87 + 456 + 0 = 666.

665979874560 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (4032).

It is a Harshad number since it is a multiple of its sum of digits (72).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 447 ways as a sum of consecutive naturals, for example, 21483221745 + ... + 21483221775.

It is an arithmetic number, because the mean of its divisors is an integer number (857891328).

Almost surely, 2^665979874560 is an apocalyptic number.

665979874560 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 665979874560, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1729508917248).

665979874560 is an abundant number, since it is smaller than the sum of its proper divisors (2793037959936).

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

665979874560 is a wasteful number, since it uses less digits than its factorization.

665979874560 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 124 (or 95 counting only the distinct ones).

The product of its (nonzero) digits is 685843200, while the sum is 72.

The spelling of 665979874560 in words is "six hundred sixty-five billion, nine hundred seventy-nine million, eight hundred seventy-four thousand, five hundred sixty".