2161109 has 4 divisors (see below), whose sum is σ = 2235660. Its totient is φ = 2086560.

The previous prime is 2161087. The next prime is 2161121. The reversal of 2161109 is 9011612.

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 1311025 + 850084 = 1145^2 + 922^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2161109 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2161129) 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, 37232 + ... + 37289.

It is an arithmetic number, because the mean of its divisors is an integer number (558915).

2^2161109 is an apocalyptic number.

2161109 is a gapful number since it is divisible by the number (29) formed by its first and last digit.

It is an amenable number.

2161109 is a deficient number, since it is larger than the sum of its proper divisors (74551).

2161109 is an equidigital number, since it uses as much as digits as its factorization.

2161109 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 74550.

The product of its (nonzero) digits is 108, while the sum is 20.

The square root of 2161109 is about 1470.0710867166. The cubic root of 2161109 is about 129.2882004694.

The spelling of 2161109 in words is "two million, one hundred sixty-one thousand, one hundred nine".