165235409 has 12 divisors (see below), whose sum is σ = 170412528. Its totient is φ = 160204200.

The previous prime is 165235403. The next prime is 165235423. The reversal of 165235409 is 904532561.

165235409 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a de Polignac number, because none of the positive numbers 2^k-165235409 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (165235403) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 289094 + ... + 289664.

It is an arithmetic number, because the mean of its divisors is an integer number (14201044).

Almost surely, 2^165235409 is an apocalyptic number.

It is an amenable number.

165235409 is a deficient number, since it is larger than the sum of its proper divisors (5177119).

165235409 is an equidigital number, since it uses as much as digits as its factorization.

165235409 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 796 (or 749 counting only the distinct ones).

The product of its (nonzero) digits is 32400, while the sum is 35.

The square root of 165235409 is about 12854.3925955294. The cubic root of 165235409 is about 548.7413742865.

The spelling of 165235409 in words is "one hundred sixty-five million, two hundred thirty-five thousand, four hundred nine".