665807053824 has 352 divisors, whose sum is σ = 2154133102080. Its totient is φ = 201470976000.

The previous prime is 665807053801. The next prime is 665807053831. The reversal of 665807053824 is 428350708566.

665807053824 is a `hidden beast` number, since 6 + 6 + 5 + 80 + 7 + 0 + 538 + 24 = 666.

It is a tau number, because it is divible by the number of its divisors (352).

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 319637487 + ... + 319639569.

Almost surely, 2^665807053824 is an apocalyptic number.

665807053824 is a gapful number since it is divisible by the number (64) 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 665807053824, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1077066551040).

665807053824 is an abundant number, since it is smaller than the sum of its proper divisors (1488326048256).

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

665807053824 is a wasteful number, since it uses less digits than its factorization.

665807053824 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3174 (or 3150 counting only the distinct ones).

The product of its (nonzero) digits is 9676800, while the sum is 54.

The spelling of 665807053824 in words is "six hundred sixty-five billion, eight hundred seven million, fifty-three thousand, eight hundred twenty-four".