16666553220245 has 4 divisors (see below), whose sum is σ = 19999863864300. Its totient is φ = 13333242576192.

The previous prime is 16666553220221. The next prime is 16666553220253. The reversal of 16666553220245 is 54202235566661.

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 3210267725284 + 13456285494961 = 1791722^2 + 3668281^2 .

It is a cyclic number.

It is not a de Polignac number, because 16666553220245 - 2²⁶ = 16666486111381 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1666655322020 + ... + 1666655322029.

It is an arithmetic number, because the mean of its divisors is an integer number (4999965966075).

Almost surely, 2^{16666553220245} is an apocalyptic number.

It is an amenable number.

16666553220245 is a deficient number, since it is larger than the sum of its proper divisors (3333310644055).

16666553220245 is an equidigital number, since it uses as much as digits as its factorization.

16666553220245 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3333310644054.

The product of its (nonzero) digits is 15552000, while the sum is 53.

The spelling of 16666553220245 in words is "sixteen trillion, six hundred sixty-six billion, five hundred fifty-three million, two hundred twenty thousand, two hundred forty-five".