66221305 has 16 divisors (see below), whose sum is σ = 83010240. Its totient is φ = 50663232.

The previous prime is 66221291. The next prime is 66221317. The reversal of 66221305 is 50312266.

It is a cyclic number.

It is not a de Polignac number, because 66221305 - 2¹⁵ = 66188537 is a prime.

It is a super-2 number, since 2×66221305² = 8770522471806050, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 66221305.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7882 + ... + 13948.

It is an arithmetic number, because the mean of its divisors is an integer number (5188140).

Almost surely, 2^66221305 is an apocalyptic number.

It is an amenable number.

66221305 is a deficient number, since it is larger than the sum of its proper divisors (16788935).

66221305 is a wasteful number, since it uses less digits than its factorization.

66221305 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6168.

The product of its (nonzero) digits is 2160, while the sum is 25.

The square root of 66221305 is about 8137.6473872981. The cubic root of 66221305 is about 404.5751883590.

The spelling of 66221305 in words is "sixty-six million, two hundred twenty-one thousand, three hundred five".