666220405298 has 54 divisors (see below), whose sum is σ = 1192124304189. Its totient is φ = 278420536800.

The previous prime is 666220405261. The next prime is 666220405303. The reversal of 666220405298 is 892504022666.

It can be written as a sum of positive squares in 2 ways, for example, as 475786791529 + 190433613769 = 689773^2 + 436387^2 .

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=577157.

It is an unprimeable number.

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 26 ways as a sum of consecutive naturals, for example, 331287113 + ... + 331289123.

Almost surely, 2^666220405298 is an apocalyptic number.

666220405298 is a deficient number, since it is larger than the sum of its proper divisors (525903898891).

666220405298 is an frugal number, since it uses more digits than its factorization.

666220405298 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4120 (or 2061 counting only the distinct ones).

The product of its (nonzero) digits is 2488320, while the sum is 50.

Multiplying 666220405298 by its sum of digits (50), we get a square (33311020264900 = 5771570²).

The spelling of 666220405298 in words is "six hundred sixty-six billion, two hundred twenty million, four hundred five thousand, two hundred ninety-eight".