165042409 has 16 divisors (see below), whose sum is σ = 200448000. Its totient is φ = 133115712.

The previous prime is 165042407. The next prime is 165042421. The reversal of 165042409 is 904240561.

It is not a de Polignac number, because 165042409 - 2¹ = 165042407 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (165042407) 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, 31992 + ... + 36790.

It is an arithmetic number, because the mean of its divisors is an integer number (12528000).

Almost surely, 2^165042409 is an apocalyptic number.

It is an amenable number.

165042409 is a deficient number, since it is larger than the sum of its proper divisors (35405591).

165042409 is an frugal number, since it uses more digits than its factorization.

165042409 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4857 (or 4823 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 31.

The square root of 165042409 is about 12846.8832406931. The cubic root of 165042409 is about 548.5276421595.

The spelling of 165042409 in words is "one hundred sixty-five million, forty-two thousand, four hundred nine".