165118521 has 32 divisors (see below), whose sum is σ = 233735040. Its totient is φ = 103564800.

The previous prime is 165118487. The next prime is 165118553. The reversal of 165118521 is 125811561.

165118521 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 165118521 - 2¹⁰ = 165117497 is a prime.

It is not an unprimeable number, because it can be changed into a prime (165118571) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 442491 + ... + 442863.

It is an arithmetic number, because the mean of its divisors is an integer number (7304220).

Almost surely, 2^165118521 is an apocalyptic number.

It is an amenable number.

165118521 is a deficient number, since it is larger than the sum of its proper divisors (68616519).

165118521 is a wasteful number, since it uses less digits than its factorization.

165118521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 537.

The product of its digits is 2400, while the sum is 30.

The square root of 165118521 is about 12849.8451741646. The cubic root of 165118521 is about 548.6119500251.

The spelling of 165118521 in words is "one hundred sixty-five million, one hundred eighteen thousand, five hundred twenty-one".