166613025381805 has 4 divisors (see below), whose sum is σ = 199935630458172. Its totient is φ = 133290420305440.

The previous prime is 166613025381799. The next prime is 166613025381823. The reversal of 166613025381805 is 508183520316661.

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 121767649686244 + 44845375695561 = 11034838^2 + 6696669^2 .

It is not a de Polignac number, because 166613025381805 - 2¹⁷ = 166613025250733 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16661302538176 + ... + 16661302538185.

It is an arithmetic number, because the mean of its divisors is an integer number (49983907614543).

Almost surely, 2^{166613025381805} is an apocalyptic number.

It is an amenable number.

166613025381805 is a deficient number, since it is larger than the sum of its proper divisors (33322605076367).

166613025381805 is an equidigital number, since it uses as much as digits as its factorization.

166613025381805 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33322605076366.

The product of its (nonzero) digits is 6220800, while the sum is 55.

The spelling of 166613025381805 in words is "one hundred sixty-six trillion, six hundred thirteen billion, twenty-five million, three hundred eighty-one thousand, eight hundred five".