165158391185 has 4 divisors (see below), whose sum is σ = 198190069428. Its totient is φ = 132126712944.

The previous prime is 165158391161. The next prime is 165158391187. The reversal of 165158391185 is 581193851561.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 581193851561 = 953 ⋅609857137.

It can be written as a sum of positive squares in 2 ways, for example, as 84054186241 + 81104204944 = 289921^2 + 284788^2 .

It is a cyclic number.

It is not a de Polignac number, because 165158391185 - 2²⁸ = 164889955729 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (165158391187) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16515839114 + ... + 16515839123.

It is an arithmetic number, because the mean of its divisors is an integer number (49547517357).

Almost surely, 2^165158391185 is an apocalyptic number.

It is an amenable number.

165158391185 is a deficient number, since it is larger than the sum of its proper divisors (33031678243).

165158391185 is an equidigital number, since it uses as much as digits as its factorization.

165158391185 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33031678242.

The product of its digits is 1296000, while the sum is 53.

The spelling of 165158391185 in words is "one hundred sixty-five billion, one hundred fifty-eight million, three hundred ninety-one thousand, one hundred eighty-five".