2117864 has 32 divisors (see below), whose sum is σ = 4622400. Its totient is φ = 890880.

The previous prime is 2117861. The next prime is 2117887. The reversal of 2117864 is 4687112.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2117861) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2984 + ... + 3624.

It is an arithmetic number, because the mean of its divisors is an integer number (144450).

2^2117864 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 2117864, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2311200).

2117864 is an abundant number, since it is smaller than the sum of its proper divisors (2504536).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

2117864 is a wasteful number, since it uses less digits than its factorization.

2117864 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 713 (or 709 counting only the distinct ones).

The product of its digits is 2688, while the sum is 29.

The square root of 2117864 is about 1455.2882875912. The cubic root of 2117864 is about 128.4200070401.

The spelling of 2117864 in words is "two million, one hundred seventeen thousand, eight hundred sixty-four".