2165780 has 12 divisors (see below), whose sum is σ = 4548180. Its totient is φ = 866304.

The previous prime is 2165773. The next prime is 2165809. The reversal of 2165780 is 875612.

It can be written as a sum of positive squares in 2 ways, for example, as 364816 + 1800964 = 604^2 + 1342^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 54125 + ... + 54164.

It is an arithmetic number, because the mean of its divisors is an integer number (379015).

2^2165780 is an apocalyptic number.

2165780 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

2165780 is an abundant number, since it is smaller than the sum of its proper divisors (2382400).

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

2165780 is a wasteful number, since it uses less digits than its factorization.

2165780 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 108298 (or 108296 counting only the distinct ones).

The product of its (nonzero) digits is 3360, while the sum is 29.

The square root of 2165780 is about 1471.6589278770. The cubic root of 2165780 is about 129.3812808607.

The spelling of 2165780 in words is "two million, one hundred sixty-five thousand, seven hundred eighty".