2156780 has 12 divisors (see below), whose sum is σ = 4529280. Its totient is φ = 862704.

The previous prime is 2156761. The next prime is 2156789. The reversal of 2156780 is 876512.

It is not an unprimeable number, because it can be changed into a prime (2156789) 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, 53900 + ... + 53939.

It is an arithmetic number, because the mean of its divisors is an integer number (377440).

2^2156780 is an apocalyptic number.

2156780 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

2156780 is an abundant number, since it is smaller than the sum of its proper divisors (2372500).

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

2156780 is a wasteful number, since it uses less digits than its factorization.

2156780 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 107848 (or 107846 counting only the distinct ones).

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

The square root of 2156780 is about 1468.5979708552. The cubic root of 2156780 is about 129.2018153854.

The spelling of 2156780 in words is "two million, one hundred fifty-six thousand, seven hundred eighty".