165423178345 has 4 divisors (see below), whose sum is σ = 198507814020. Its totient is φ = 132338542672.

The previous prime is 165423178259. The next prime is 165423178367. The reversal of 165423178345 is 543871324561.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 543871324561 = 166799 ⋅3260639.

It can be written as a sum of positive squares in 2 ways, for example, as 113049940441 + 52373237904 = 336229^2 + 228852^2 .

It is a cyclic number.

It is not a de Polignac number, because 165423178345 - 2²⁵ = 165389623913 is a prime.

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, 16542317830 + ... + 16542317839.

It is an arithmetic number, because the mean of its divisors is an integer number (49626953505).

Almost surely, 2^165423178345 is an apocalyptic number.

It is an amenable number.

165423178345 is a deficient number, since it is larger than the sum of its proper divisors (33084635675).

165423178345 is an equidigital number, since it uses as much as digits as its factorization.

165423178345 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33084635674.

The product of its digits is 2419200, while the sum is 49.

The spelling of 165423178345 in words is "one hundred sixty-five billion, four hundred twenty-three million, one hundred seventy-eight thousand, three hundred forty-five".