165512309 has 6 divisors (see below), whose sum is σ = 171291330. Its totient is φ = 159738096.

The previous prime is 165512261. The next prime is 165512327. The reversal of 165512309 is 903215561.

It can be written as a sum of positive squares in 3 ways, for example, as 2235025 + 163277284 = 1495^2 + 12778^2 .

It is a de Polignac number, because none of the positive numbers 2^k-165512309 is a prime.

It is a super-2 number, since 2×165512309² = 54788648861022962, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (165512339) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 68087 + ... + 70475.

It is an arithmetic number, because the mean of its divisors is an integer number (28548555).

Almost surely, 2^165512309 is an apocalyptic number.

It is an amenable number.

165512309 is a deficient number, since it is larger than the sum of its proper divisors (5779021).

165512309 is an frugal number, since it uses more digits than its factorization.

165512309 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4807 (or 2418 counting only the distinct ones).

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

The square root of 165512309 is about 12865.1587242443. The cubic root of 165512309 is about 549.0477284946.

The spelling of 165512309 in words is "one hundred sixty-five million, five hundred twelve thousand, three hundred nine".