66668891600 has 30 divisors (see below), whose sum is σ = 160172013030. Its totient is φ = 26667556480.

The previous prime is 66668891591. The next prime is 66668891683. The reversal of 66668891600 is 619886666.

66668891600 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 3 ways, for example, as 3717184 + 66665174416 = 1928^2 + 258196^2 .

It is a super-2 number, since 2×66668891600² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

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, 83335715 + ... + 83336514.

It is an arithmetic number, because the mean of its divisors is an integer number (5339067101).

Almost surely, 2^66668891600 is an apocalyptic number.

It is an amenable number.

66668891600 is an abundant number, since it is smaller than the sum of its proper divisors (93503121430).

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

66668891600 is a wasteful number, since it uses less digits than its factorization.

66668891600 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 166672247 (or 166672236 counting only the distinct ones).

The product of its (nonzero) digits is 4478976, while the sum is 56.

The spelling of 66668891600 in words is "sixty-six billion, six hundred sixty-eight million, eight hundred ninety-one thousand, six hundred".