66221317 has 2 divisors, whose sum is σ = 66221318. Its totient is φ = 66221316.

The previous prime is 66221291. The next prime is 66221329. The reversal of 66221317 is 71312266.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 43046721 + 23174596 = 6561^2 + 4814^2 .

It is a cyclic number.

It is not a de Polignac number, because 66221317 - 2⁷ = 66221189 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66221377) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33110658 + 33110659.

It is an arithmetic number, because the mean of its divisors is an integer number (33110659).

Almost surely, 2^66221317 is an apocalyptic number.

It is an amenable number.

66221317 is a deficient number, since it is larger than the sum of its proper divisors (1).

66221317 is an equidigital number, since it uses as much as digits as its factorization.

66221317 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3024, while the sum is 28.

The square root of 66221317 is about 8137.6481246119. The cubic root of 66221317 is about 404.5752127968.

The spelling of 66221317 in words is "sixty-six million, two hundred twenty-one thousand, three hundred seventeen".