165609211 has 4 divisors (see below), whose sum is σ = 169460632. Its totient is φ = 161757792.

The previous prime is 165609203. The next prime is 165609217. The reversal of 165609211 is 112906561.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 112906561 = 883 ⋅127867.

It is a cyclic number.

It is not a de Polignac number, because 165609211 - 2³ = 165609203 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (165609217) 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, 1925646 + ... + 1925731.

It is an arithmetic number, because the mean of its divisors is an integer number (42365158).

Almost surely, 2^165609211 is an apocalyptic number.

165609211 is a deficient number, since it is larger than the sum of its proper divisors (3851421).

165609211 is an equidigital number, since it uses as much as digits as its factorization.

165609211 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3851420.

The product of its (nonzero) digits is 3240, while the sum is 31.

The square root of 165609211 is about 12868.9242363144. The cubic root of 165609211 is about 549.1548573715.

The spelling of 165609211 in words is "one hundred sixty-five million, six hundred nine thousand, two hundred eleven".