165515557 has 16 divisors (see below), whose sum is σ = 176172480. Its totient is φ = 155232000.

The previous prime is 165515531. The next prime is 165515561. The reversal of 165515557 is 755515561.

165515557 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-165515557 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 (165515057) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 412557 + ... + 412957.

It is an arithmetic number, because the mean of its divisors is an integer number (11010780).

Almost surely, 2^165515557 is an apocalyptic number.

It is an amenable number.

165515557 is a deficient number, since it is larger than the sum of its proper divisors (10656923).

165515557 is a wasteful number, since it uses less digits than its factorization.

165515557 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 804.

The product of its digits is 131250, while the sum is 40.

The square root of 165515557 is about 12865.2849560358. The cubic root of 165515557 is about 549.0513199603.

The spelling of 165515557 in words is "one hundred sixty-five million, five hundred fifteen thousand, five hundred fifty-seven".