18165161 has 4 divisors (see below), whose sum is σ = 20760192. Its totient is φ = 15570132.

The previous prime is 18165143. The next prime is 18165211. The reversal of 18165161 is 16156181.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18165161 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18162161) 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, 1297505 + ... + 1297518.

It is an arithmetic number, because the mean of its divisors is an integer number (5190048).

Almost surely, 2^18165161 is an apocalyptic number.

It is an amenable number.

18165161 is a deficient number, since it is larger than the sum of its proper divisors (2595031).

18165161 is an equidigital number, since it uses as much as digits as its factorization.

18165161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2595030.

The product of its digits is 1440, while the sum is 29.

The square root of 18165161 is about 4262.0606518444. The cubic root of 18165161 is about 262.8732636925.

The spelling of 18165161 in words is "eighteen million, one hundred sixty-five thousand, one hundred sixty-one".