66328166233261 has 4 divisors (see below), whose sum is σ = 66984880750524. Its totient is φ = 65671451716000.

The previous prime is 66328166233213. The next prime is 66328166233297. The reversal of 66328166233261 is 16233266182366.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 64961182022500 + 1366984210761 = 8059850^2 + 1169181^2 .

It is a cyclic number.

It is not a de Polignac number, because 66328166233261 - 2¹⁵ = 66328166200493 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 (66328166233361) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 328357258480 + ... + 328357258681.

It is an arithmetic number, because the mean of its divisors is an integer number (16746220187631).

Almost surely, 2^{66328166233261} is an apocalyptic number.

It is an amenable number.

66328166233261 is a deficient number, since it is larger than the sum of its proper divisors (656714517263).

66328166233261 is a wasteful number, since it uses less digits than its factorization.

66328166233261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 656714517262.

The product of its digits is 13436928, while the sum is 55.

The spelling of 66328166233261 in words is "sixty-six trillion, three hundred twenty-eight billion, one hundred sixty-six million, two hundred thirty-three thousand, two hundred sixty-one".