2156786 has 4 divisors (see below), whose sum is σ = 3235182. Its totient is φ = 1078392.

The previous prime is 2156761. The next prime is 2156789. The reversal of 2156786 is 6876512.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 1380625 + 776161 = 1175^2 + 881^2 .

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 as a sum of consecutive naturals, namely, 539195 + ... + 539198.

2^2156786 is an apocalyptic number.

2156786 is a deficient number, since it is larger than the sum of its proper divisors (1078396).

2156786 is a wasteful number, since it uses less digits than its factorization.

2156786 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1078395.

The product of its digits is 20160, while the sum is 35.

The square root of 2156786 is about 1468.6000136184. The cubic root of 2156786 is about 129.2019351952.

The spelling of 2156786 in words is "two million, one hundred fifty-six thousand, seven hundred eighty-six".