165891139 has 4 divisors (see below), whose sum is σ = 166733424. Its totient is φ = 165048856.

The previous prime is 165891127. The next prime is 165891161. The reversal of 165891139 is 931198561.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 165891139 - 2¹³ = 165882947 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 165891095 and 165891104.

It is not an unprimeable number, because it can be changed into a prime (165891169) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 420847 + ... + 421240.

It is an arithmetic number, because the mean of its divisors is an integer number (41683356).

Almost surely, 2^165891139 is an apocalyptic number.

165891139 is a deficient number, since it is larger than the sum of its proper divisors (842285).

165891139 is an equidigital number, since it uses as much as digits as its factorization.

165891139 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 842284.

The product of its digits is 58320, while the sum is 43.

The square root of 165891139 is about 12879.8734077630. The cubic root of 165891139 is about 549.4663021233.

The spelling of 165891139 in words is "one hundred sixty-five million, eight hundred ninety-one thousand, one hundred thirty-nine".