666905599400 has 24 divisors (see below), whose sum is σ = 1550555519070. Its totient is φ = 266762239680.

The previous prime is 666905599379. The next prime is 666905599417. The reversal of 666905599400 is 4995509666.

It can be written as a sum of positive squares in 3 ways, for example, as 633402689956 + 33502909444 = 795866^2 + 183038^2 .

It is a super-2 number, since 2×666905599400² (a number of 24 digits) contains 22 as substring.

It is a hoax number, since the sum of its digits (59) coincides with the sum of the digits of its distinct prime factors.

It is a self number, because there is not a number n which added to its sum of digits gives 666905599400.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1667263799 + ... + 1667264198.

Almost surely, 2^666905599400 is an apocalyptic number.

It is an amenable number.

666905599400 is an abundant number, since it is smaller than the sum of its proper divisors (883649919670).

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

666905599400 is a wasteful number, since it uses less digits than its factorization.

666905599400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3334528013 (or 3334528004 counting only the distinct ones).

The product of its (nonzero) digits is 15746400, while the sum is 59.

The spelling of 666905599400 in words is "six hundred sixty-six billion, nine hundred five million, five hundred ninety-nine thousand, four hundred".