166845026405 has 4 divisors (see below), whose sum is σ = 200214031692. Its totient is φ = 133476021120.

The previous prime is 166845026393. The next prime is 166845026407. The reversal of 166845026405 is 504620548661.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 504620548661 = 560227 ⋅900743.

It can be written as a sum of positive squares in 2 ways, for example, as 32021670916 + 134823355489 = 178946^2 + 367183^2 .

It is not a de Polignac number, because 166845026405 - 2¹⁶ = 166844960869 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 166845026405.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (166845026407) 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, 16684502636 + ... + 16684502645.

It is an arithmetic number, because the mean of its divisors is an integer number (50053507923).

Almost surely, 2^166845026405 is an apocalyptic number.

It is an amenable number.

166845026405 is a deficient number, since it is larger than the sum of its proper divisors (33369005287).

166845026405 is an equidigital number, since it uses as much as digits as its factorization.

166845026405 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33369005286.

The product of its (nonzero) digits is 1382400, while the sum is 47.

The spelling of 166845026405 in words is "one hundred sixty-six billion, eight hundred forty-five million, twenty-six thousand, four hundred five".