66221867807 has 16 divisors (see below), whose sum is σ = 71204646240. Its totient is φ = 61460687232.

The previous prime is 66221867783. The next prime is 66221867809. The reversal of 66221867807 is 70876812266.

It is a cyclic number.

It is not a de Polignac number, because 66221867807 - 2¹² = 66221863711 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66221867809) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 282728 + ... + 460845.

It is an arithmetic number, because the mean of its divisors is an integer number (4450290390).

Almost surely, 2^66221867807 is an apocalyptic number.

66221867807 is a deficient number, since it is larger than the sum of its proper divisors (4982778433).

66221867807 is a wasteful number, since it uses less digits than its factorization.

66221867807 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 743722.

The product of its (nonzero) digits is 2709504, while the sum is 53.

The spelling of 66221867807 in words is "sixty-six billion, two hundred twenty-one million, eight hundred sixty-seven thousand, eight hundred seven".