2156785 has 16 divisors (see below), whose sum is σ = 2770560. Its totient is φ = 1607040.

The previous prime is 2156761. The next prime is 2156789. The reversal of 2156785 is 5876512.

It is not a de Polignac number, because 2156785 - 2⁵ = 2156753 is a prime.

2156785 is a lucky number.

It is a self number, because there is not a number n which added to its sum of digits gives 2156785.

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 15 ways as a sum of consecutive naturals, for example, 6780 + ... + 7090.

It is an arithmetic number, because the mean of its divisors is an integer number (173160).

2^2156785 is an apocalyptic number.

It is an amenable number.

2156785 is a deficient number, since it is larger than the sum of its proper divisors (613775).

2156785 is a wasteful number, since it uses less digits than its factorization.

2156785 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 408.

The product of its digits is 16800, while the sum is 34.

The square root of 2156785 is about 1468.5996731581. The cubic root of 2156785 is about 129.2019152269.

The spelling of 2156785 in words is "two million, one hundred fifty-six thousand, seven hundred eighty-five".