665072870400 has 297 divisors, whose sum is σ = 2382677915241. Its totient is φ = 177248378880.

The previous prime is 665072870389. The next prime is 665072870477. The reversal of 665072870400 is 4078270566.

The square root of 665072870400 is 815520.

It is a perfect power (a square), and thus also a powerful number.

665072870400 is a `hidden beast` number, since 66 + 50 + 72 + 8 + 70 + 400 = 666.

It can be written as a sum of positive squares in only one way, i.e., 239426233344 + 425646637056 = 489312^2 + 652416^2 .

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

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 26 ways as a sum of consecutive naturals, for example, 391448751 + ... + 391450449.

Almost surely, 2^665072870400 is an apocalyptic number.

665072870400 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

665072870400 is the 815520-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 665072870400

665072870400 is an abundant number, since it is smaller than the sum of its proper divisors (1717605044841).

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

665072870400 is an equidigital number, since it uses as much as digits as its factorization.

665072870400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3434 (or 1709 counting only the distinct ones).

The product of its (nonzero) digits is 564480, while the sum is 45.

The spelling of 665072870400 in words is "six hundred sixty-five billion, seventy-two million, eight hundred seventy thousand, four hundred".