2118161 has 4 divisors (see below), whose sum is σ = 2122212. Its totient is φ = 2114112.

The previous prime is 2118121. The next prime is 2118163. The reversal of 2118161 is 1618112.

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 309136 + 1809025 = 556^2 + 1345^2 .

It is a cyclic number.

It is not a de Polignac number, because 2118161 - 2¹⁸ = 1856017 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2118163) 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, 1100 + ... + 2333.

It is an arithmetic number, because the mean of its divisors is an integer number (530553).

2^2118161 is an apocalyptic number.

It is an amenable number.

2118161 is a deficient number, since it is larger than the sum of its proper divisors (4051).

2118161 is an equidigital number, since it uses as much as digits as its factorization.

2118161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4050.

The product of its digits is 96, while the sum is 20.

The square root of 2118161 is about 1455.3903256515. The cubic root of 2118161 is about 128.4260097799.

The spelling of 2118161 in words is "two million, one hundred eighteen thousand, one hundred sixty-one".