66621900600 has 144 divisors (see below), whose sum is σ = 232025331720. Its totient is φ = 17765827200.

The previous prime is 66621900589. The next prime is 66621900601. The reversal of 66621900600 is 600912666.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66621900601) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 636811 + ... + 734010.

Almost surely, 2^66621900600 is an apocalyptic number.

66621900600 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

66621900600 is an abundant number, since it is smaller than the sum of its proper divisors (165403431120).

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

66621900600 is a wasteful number, since it uses less digits than its factorization.

66621900600 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1370852 (or 1370831 counting only the distinct ones).

The product of its (nonzero) digits is 23328, while the sum is 36.

The spelling of 66621900600 in words is "sixty-six billion, six hundred twenty-one million, nine hundred thousand, six hundred".