2156897 has 2 divisors, whose sum is σ = 2156898. Its totient is φ = 2156896.

The previous prime is 2156879. The next prime is 2156939. The reversal of 2156897 is 7986512.

Together with previous prime (2156879) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1449616 + 707281 = 1204^2 + 841^2 .

It is a cyclic number.

It is not a de Polignac number, because 2156897 - 2¹⁴ = 2140513 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 2156897.

It is not a weakly prime, because it can be changed into another prime (2156857) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1078448 + 1078449.

It is an arithmetic number, because the mean of its divisors is an integer number (1078449).

2^2156897 is an apocalyptic number.

It is an amenable number.

2156897 is a deficient number, since it is larger than the sum of its proper divisors (1).

2156897 is an equidigital number, since it uses as much as digits as its factorization.

2156897 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 30240, while the sum is 38.

The square root of 2156897 is about 1468.6378042254. The cubic root of 2156897 is about 129.2041516365.

The spelling of 2156897 in words is "two million, one hundred fifty-six thousand, eight hundred ninety-seven".