2118991 has 8 divisors (see below), whose sum is σ = 2433024. Its totient is φ = 1807800.

The previous prime is 2118973. The next prime is 2119031. The reversal of 2118991 is 1998112.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 2118991 - 2⁵ = 2118959 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2118091) 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, 1266 + ... + 2416.

It is an arithmetic number, because the mean of its divisors is an integer number (304128).

2^2118991 is an apocalyptic number.

2118991 is a deficient number, since it is larger than the sum of its proper divisors (314033).

2118991 is a wasteful number, since it uses less digits than its factorization.

2118991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1421.

The product of its digits is 1296, while the sum is 31.

The square root of 2118991 is about 1455.6754445961. The cubic root of 2118991 is about 128.4427821386.

The spelling of 2118991 in words is "two million, one hundred eighteen thousand, nine hundred ninety-one".