666172140800 has 54 divisors (see below), whose sum is σ = 1648880153718. Its totient is φ = 266468853760.

The previous prime is 666172140779. The next prime is 666172140811. The reversal of 666172140800 is 8041271666.

It can be written as a sum of positive squares in 3 ways, for example, as 193290363904 + 472881776896 = 439648^2 + 687664^2 .

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 5 ways as a sum of consecutive naturals, for example, 52038299 + ... + 52051098.

Almost surely, 2^666172140800 is an apocalyptic number.

It is an amenable number.

666172140800 is an abundant number, since it is smaller than the sum of its proper divisors (982708012918).

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

666172140800 is a wasteful number, since it uses less digits than its factorization.

666172140800 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 104089423 (or 104089404 counting only the distinct ones).

The product of its (nonzero) digits is 96768, while the sum is 41.

The spelling of 666172140800 in words is "six hundred sixty-six billion, one hundred seventy-two million, one hundred forty thousand, eight hundred".