165511161 has 8 divisors (see below), whose sum is σ = 245201760. Its totient is φ = 110340756.

The previous prime is 165511123. The next prime is 165511163. The reversal of 165511161 is 161115561.

165511161 is a `hidden beast` number, since 1 + 655 + 1 + 1 + 1 + 6 + 1 = 666.

It is not a de Polignac number, because 165511161 - 2⁹ = 165510649 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27), and also a Moran number because the ratio is a prime number: 6130043 = 165511161 / (1 + 6 + 5 + 5 + 1 + 1 + 1 + 6 + 1).

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (165511163) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3064995 + ... + 3065048.

It is an arithmetic number, because the mean of its divisors is an integer number (30650220).

Almost surely, 2^165511161 is an apocalyptic number.

It is an amenable number.

165511161 is a deficient number, since it is larger than the sum of its proper divisors (79690599).

165511161 is an equidigital number, since it uses as much as digits as its factorization.

165511161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6130052 (or 6130046 counting only the distinct ones).

The product of its digits is 900, while the sum is 27.

The square root of 165511161 is about 12865.1141075390. The cubic root of 165511161 is about 549.0464590860.

The spelling of 165511161 in words is "one hundred sixty-five million, five hundred eleven thousand, one hundred sixty-one".