66221004 has 24 divisors (see below), whose sum is σ = 162648640. Its totient is φ = 20911824.

The previous prime is 66221003. The next prime is 66221021. The reversal of 66221004 is 40012266.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (66221003) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 144994 + ... + 145449.

Almost surely, 2^66221004 is an apocalyptic number.

It is an amenable number.

66221004 is an abundant number, since it is smaller than the sum of its proper divisors (96427636).

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

66221004 is a wasteful number, since it uses less digits than its factorization.

66221004 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 290469 (or 290467 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 21.

The square root of 66221004 is about 8137.6288929884. The cubic root of 66221004 is about 404.5745753775.

It can be divided in two parts, 6622 and 1004, that added together give a triangular number (7626 = T₁₂₃).

The spelling of 66221004 in words is "sixty-six million, two hundred twenty-one thousand, four".