2156857 has 2 divisors, whose sum is σ = 2156858. Its totient is φ = 2156856.

The previous prime is 2156851. The next prime is 2156867. The reversal of 2156857 is 7586512.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1510441 + 646416 = 1229^2 + 804^2 .

It is a cyclic number.

It is not a de Polignac number, because 2156857 - 2³ = 2156849 is a prime.

It is not a weakly prime, because it can be changed into another prime (2156851) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1078428 + 1078429.

It is an arithmetic number, because the mean of its divisors is an integer number (1078429).

2^2156857 is an apocalyptic number.

It is an amenable number.

2156857 is a deficient number, since it is larger than the sum of its proper divisors (1).

2156857 is an equidigital number, since it uses as much as digits as its factorization.

2156857 is an evil number, because the sum of its binary digits is even.

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

The square root of 2156857 is about 1468.6241861007. The cubic root of 2156857 is about 129.2033529276.

The spelling of 2156857 in words is "two million, one hundred fifty-six thousand, eight hundred fifty-seven".