66221590 has 16 divisors (see below), whose sum is σ = 121735872. Its totient is φ = 25924864.

The previous prime is 66221569. The next prime is 66221621. The reversal of 66221590 is 9512266.

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, 69979 + ... + 70918.

It is an arithmetic number, because the mean of its divisors is an integer number (7608492).

Almost surely, 2^66221590 is an apocalyptic number.

66221590 is a deficient number, since it is larger than the sum of its proper divisors (55514282).

66221590 is a wasteful number, since it uses less digits than its factorization.

66221590 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 140951.

The product of its (nonzero) digits is 6480, while the sum is 31.

The square root of 66221590 is about 8137.6648984829. The cubic root of 66221590 is about 404.5757687551.

The spelling of 66221590 in words is "sixty-six million, two hundred twenty-one thousand, five hundred ninety".