2118191 has 4 divisors (see below), whose sum is σ = 2121384. Its totient is φ = 2115000.

The previous prime is 2118187. The next prime is 2118209. The reversal of 2118191 is 1918112.

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 2118191 - 2² = 2118187 is a prime.

It is a super-2 number, since 2×2118191² = 8973466224962, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2118121) 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, 185 + ... + 2066.

It is an arithmetic number, because the mean of its divisors is an integer number (530346).

2^2118191 is an apocalyptic number.

2118191 is a deficient number, since it is larger than the sum of its proper divisors (3193).

2118191 is an equidigital number, since it uses as much as digits as its factorization.

2118191 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3192.

The product of its digits is 144, while the sum is 23.

The square root of 2118191 is about 1455.4006321285. The cubic root of 2118191 is about 128.4266160861.

The spelling of 2118191 in words is "two million, one hundred eighteen thousand, one hundred ninety-one".