165257913 has 4 divisors (see below), whose sum is σ = 220343888. Its totient is φ = 110171940.

The previous prime is 165257903. The next prime is 165257927. The reversal of 165257913 is 319752561.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 319752561 = 3 ⋅106584187.

It is not a de Polignac number, because 165257913 - 2⁶ = 165257849 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (165257903) 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, 27542983 + ... + 27542988.

It is an arithmetic number, because the mean of its divisors is an integer number (55085972).

Almost surely, 2^165257913 is an apocalyptic number.

It is an amenable number.

165257913 is a deficient number, since it is larger than the sum of its proper divisors (55085975).

165257913 is an equidigital number, since it uses as much as digits as its factorization.

165257913 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 55085974.

The product of its digits is 56700, while the sum is 39.

The square root of 165257913 is about 12855.2679085268. The cubic root of 165257913 is about 548.7662848376.

The spelling of 165257913 in words is "one hundred sixty-five million, two hundred fifty-seven thousand, nine hundred thirteen".