2158820 has 12 divisors (see below), whose sum is σ = 4533564. Its totient is φ = 863520.

The previous prime is 2158817. The next prime is 2158823. The reversal of 2158820 is 288512.

It is an interprime number because it is at equal distance from previous prime (2158817) and next prime (2158823).

It can be written as a sum of positive squares in 2 ways, for example, as 1308736 + 850084 = 1144^2 + 922^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 2158820.

It is not an unprimeable number, because it can be changed into a prime (2158823) 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, 53951 + ... + 53990.

It is an arithmetic number, because the mean of its divisors is an integer number (377797).

2^2158820 is an apocalyptic number.

2158820 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

2158820 is an abundant number, since it is smaller than the sum of its proper divisors (2374744).

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

2158820 is a wasteful number, since it uses less digits than its factorization.

2158820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 107950 (or 107948 counting only the distinct ones).

The product of its (nonzero) digits is 1280, while the sum is 26.

The square root of 2158820 is about 1469.2923466758. The cubic root of 2158820 is about 129.2425379203.

The spelling of 2158820 in words is "two million, one hundred fifty-eight thousand, eight hundred twenty".