165125309 has 4 divisors (see below), whose sum is σ = 165288060. Its totient is φ = 164962560.

The previous prime is 165125297. The next prime is 165125383. The reversal of 165125309 is 903521561.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 95452900 + 69672409 = 9770^2 + 8347^2 .

It is a cyclic number.

It is not a de Polignac number, because 165125309 - 2⁴ = 165125293 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 (165125509) 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, 79844 + ... + 81885.

It is an arithmetic number, because the mean of its divisors is an integer number (41322015).

Almost surely, 2^165125309 is an apocalyptic number.

It is an amenable number.

165125309 is a deficient number, since it is larger than the sum of its proper divisors (162751).

165125309 is a wasteful number, since it uses less digits than its factorization.

165125309 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 162750.

The product of its (nonzero) digits is 8100, while the sum is 32.

The square root of 165125309 is about 12850.1092991461. The cubic root of 165125309 is about 548.6194677097.

The spelling of 165125309 in words is "one hundred sixty-five million, one hundred twenty-five thousand, three hundred nine".