165591985279 has 12 divisors (see below), whose sum is σ = 192634096008. Its totient is φ = 141931062000.

The previous prime is 165591985267. The next prime is 165591985283. The reversal of 165591985279 is 972589195561.

It is not a de Polignac number, because 165591985279 - 2¹³ = 165591977087 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (165591985579) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2464429 + ... + 2530729.

It is an arithmetic number, because the mean of its divisors is an integer number (16052841334).

Almost surely, 2^165591985279 is an apocalyptic number.

165591985279 is a deficient number, since it is larger than the sum of its proper divisors (27042110729).

165591985279 is an equidigital number, since it uses as much as digits as its factorization.

165591985279 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 117286 (or 117279 counting only the distinct ones).

The product of its digits is 61236000, while the sum is 67.

The spelling of 165591985279 in words is "one hundred sixty-five billion, five hundred ninety-one million, nine hundred eighty-five thousand, two hundred seventy-nine".