666509372458880 has 256 divisors, whose sum is σ = 1661463063691200. Its totient is φ = 255448695570432.

The previous prime is 666509372458879. The next prime is 666509372458931. The reversal of 666509372458880 is 88854273905666.

It is a hoax number, since the sum of its digits (77) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 9826284806 + ... + 9826352634.

Almost surely, 2^{666509372458880} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 666509372458880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (830731531845600).

666509372458880 is an abundant number, since it is smaller than the sum of its proper divisors (994953691232320).

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

666509372458880 is a wasteful number, since it uses less digits than its factorization.

666509372458880 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 74681 (or 74669 counting only the distinct ones).

The product of its (nonzero) digits is 4180377600, while the sum is 77.

The spelling of 666509372458880 in words is "six hundred sixty-six trillion, five hundred nine billion, three hundred seventy-two million, four hundred fifty-eight thousand, eight hundred eighty".