66221297254788 has 96 divisors (see below), whose sum is σ = 170329765178496. Its totient is φ = 19895182820352.

The previous prime is 66221297254787. The next prime is 66221297254793. The reversal of 66221297254788 is 88745279212266.

It is not an unprimeable number, because it can be changed into a prime (66221297254781) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 18137206 + ... + 21480242.

It is an arithmetic number, because the mean of its divisors is an integer number (1774268387276).

Almost surely, 2^{66221297254788} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66221297254788, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (85164882589248).

66221297254788 is an abundant number, since it is smaller than the sum of its proper divisors (104108467923708).

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

66221297254788 is a wasteful number, since it uses less digits than its factorization.

66221297254788 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3346053 (or 3346051 counting only the distinct ones).

The product of its digits is 325140480, while the sum is 69.

The spelling of 66221297254788 in words is "sixty-six trillion, two hundred twenty-one billion, two hundred ninety-seven million, two hundred fifty-four thousand, seven hundred eighty-eight".