666957784320 has 504 divisors, whose sum is σ = 2521396231200. Its totient is φ = 168490119168.

The previous prime is 666957784289. The next prime is 666957784349. The reversal of 666957784320 is 23487759666.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 55 ways as a sum of consecutive naturals, for example, 17710471 + ... + 17748089.

It is an arithmetic number, because the mean of its divisors is an integer number (5002770300).

Almost surely, 2^666957784320 is an apocalyptic number.

666957784320 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 666957784320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1260698115600).

666957784320 is an abundant number, since it is smaller than the sum of its proper divisors (1854438446880).

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

666957784320 is an equidigital number, since it uses as much as digits as its factorization.

666957784320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 37677 (or 37648 counting only the distinct ones).

The product of its (nonzero) digits is 91445760, while the sum is 63.

The spelling of 666957784320 in words is "six hundred sixty-six billion, nine hundred fifty-seven million, seven hundred eighty-four thousand, three hundred twenty".