66221012 has 24 divisors (see below), whose sum is σ = 136147872. Its totient is φ = 27784800.

The previous prime is 66221003. The next prime is 66221021. The reversal of 66221012 is 21012266.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (66221003) and next prime (66221021).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 57314 + ... + 58457.

It is an arithmetic number, because the mean of its divisors is an integer number (5672828).

Almost surely, 2^66221012 is an apocalyptic number.

It is an amenable number.

66221012 is an abundant number, since it is smaller than the sum of its proper divisors (69926860).

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

66221012 is a wasteful number, since it uses less digits than its factorization.

66221012 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 115799 (or 115797 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 20.

The square root of 66221012 is about 8137.6293845321. The cubic root of 66221012 is about 404.5745916694.

Adding to 66221012 its reverse (21012266), we get a palindrome (87233278).

The spelling of 66221012 in words is "sixty-six million, two hundred twenty-one thousand, twelve".