66221867808 has 72 divisors (see below), whose sum is σ = 188358036048. Its totient is φ = 22069314432.

The previous prime is 66221867783. The next prime is 66221867809. The reversal of 66221867808 is 80876812266.

66221867808 is a `hidden beast` number, since 6 + 622 + 1 + 8 + 6 + 7 + 8 + 0 + 8 = 666.

It is a tau number, because it is divible by the number of its divisors (72).

It is not an unprimeable number, because it can be changed into a prime (66221867809) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1518435 + ... + 1561437.

It is an arithmetic number, because the mean of its divisors is an integer number (2616083834).

Almost surely, 2^66221867808 is an apocalyptic number.

It is an amenable number.

66221867808 is an abundant number, since it is smaller than the sum of its proper divisors (122136168240).

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

66221867808 is a wasteful number, since it uses less digits than its factorization.

66221867808 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 48366 (or 48355 counting only the distinct ones).

The product of its (nonzero) digits is 3096576, while the sum is 54.

The spelling of 66221867808 in words is "sixty-six billion, two hundred twenty-one million, eight hundred sixty-seven thousand, eight hundred eight".