2117989 has 4 divisors (see below), whose sum is σ = 2138656. Its totient is φ = 2097324.

The previous prime is 2117977. The next prime is 2118007. The reversal of 2117989 is 9897112.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 2117989 - 2⁷ = 2117861 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 (2117389) 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, 10179 + ... + 10384.

It is an arithmetic number, because the mean of its divisors is an integer number (534664).

2^2117989 is an apocalyptic number.

It is an amenable number.

2117989 is a deficient number, since it is larger than the sum of its proper divisors (20667).

2117989 is a wasteful number, since it uses less digits than its factorization.

2117989 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20666.

The product of its digits is 9072, while the sum is 37.

The square root of 2117989 is about 1455.3312337746. The cubic root of 2117989 is about 128.4225335142.

The spelling of 2117989 in words is "two million, one hundred seventeen thousand, nine hundred eighty-nine".