165261613 has 4 divisors (see below), whose sum is σ = 180285408. Its totient is φ = 150237820.

The previous prime is 165261587. The next prime is 165261617. The reversal of 165261613 is 316162561.

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.

It is a cyclic number.

It is not a de Polignac number, because 165261613 - 2⁵ = 165261581 is a prime.

It is a super-2 number, since 2×165261613² = 54622801462723538, which contains 22 as substring.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (165261617) 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, 7511881 + ... + 7511902.

It is an arithmetic number, because the mean of its divisors is an integer number (45071352).

Almost surely, 2^165261613 is an apocalyptic number.

It is an amenable number.

165261613 is a deficient number, since it is larger than the sum of its proper divisors (15023795).

165261613 is a wasteful number, since it uses less digits than its factorization.

165261613 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15023794.

The product of its digits is 6480, while the sum is 31.

The square root of 165261613 is about 12855.4118175965. The cubic root of 165261613 is about 548.7703802948.

The spelling of 165261613 in words is "one hundred sixty-five million, two hundred sixty-one thousand, six hundred thirteen".