2118931 has 4 divisors (see below), whose sum is σ = 2243592. Its totient is φ = 1994272.

The previous prime is 2118923. The next prime is 2118959. The reversal of 2118931 is 1398112.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 2118931 - 2³ = 2118923 is a prime.

It is a super-2 number, since 2×2118931² = 8979737165522, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 2118896 and 2118905.

It is not an unprimeable number, because it can be changed into a prime (2118031) 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, 62305 + ... + 62338.

It is an arithmetic number, because the mean of its divisors is an integer number (560898).

2^2118931 is an apocalyptic number.

2118931 is a deficient number, since it is larger than the sum of its proper divisors (124661).

2118931 is a wasteful number, since it uses less digits than its factorization.

2118931 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 124660.

The product of its digits is 432, while the sum is 25.

The square root of 2118931 is about 1455.6548354607. The cubic root of 2118931 is about 128.4415698258.

The spelling of 2118931 in words is "two million, one hundred eighteen thousand, nine hundred thirty-one".