2158864 has 20 divisors (see below), whose sum is σ = 4429404. Its totient is φ = 1015808.

The previous prime is 2158859. The next prime is 2158889. The reversal of 2158864 is 4688512.

It can be written as a sum of positive squares in 2 ways, for example, as 1982464 + 176400 = 1408^2 + 420^2 .

It is a Harshad number since it is a multiple of its sum of digits (34).

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 3697 + ... + 4240.

2^2158864 is an apocalyptic number.

It is an amenable number.

2158864 is an abundant number, since it is smaller than the sum of its proper divisors (2270540).

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

2158864 is a wasteful number, since it uses less digits than its factorization.

2158864 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7962 (or 7956 counting only the distinct ones).

The product of its digits is 15360, while the sum is 34.

The square root of 2158864 is about 1469.3073197939. The cubic root of 2158864 is about 129.2434159668.

It can be divided in two parts, 21 and 58864, that added together give a palindrome (58885).

The spelling of 2158864 in words is "two million, one hundred fifty-eight thousand, eight hundred sixty-four".