665346700800 has 1200 divisors, whose sum is σ = 2577665114112. Its totient is φ = 169305292800.

The previous prime is 665346700709. The next prime is 665346700817. The reversal of 665346700800 is 8007643566.

665346700800 is a `hidden beast` number, since 66 + 53 + 467 + 0 + 0 + 80 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (1200).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 119 ways as a sum of consecutive naturals, for example, 4081881519 + ... + 4081881681.

Almost surely, 2^665346700800 is an apocalyptic number.

665346700800 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 665346700800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1288832557056).

665346700800 is an abundant number, since it is smaller than the sum of its proper divisors (1912318413312).

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

665346700800 is a wasteful number, since it uses less digits than its factorization.

665346700800 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 361 (or 331 counting only the distinct ones).

The product of its (nonzero) digits is 725760, while the sum is 45.

The spelling of 665346700800 in words is "six hundred sixty-five billion, three hundred forty-six million, seven hundred thousand, eight hundred".