811897 has 2 divisors, whose sum is σ = 811898. Its totient is φ = 811896.

The previous prime is 811879. The next prime is 811919. The reversal of 811897 is 798118.

Together with previous prime (811879) 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., 767376 + 44521 = 876^2 + 211^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-811897 is a prime.

811897 is a lucky number.

It is not a weakly prime, because it can be changed into another prime (811297) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 405948 + 405949.

It is an arithmetic number, because the mean of its divisors is an integer number (405949).

2⁸¹¹⁸⁹⁷ is an apocalyptic number.

It is an amenable number.

811897 is a deficient number, since it is larger than the sum of its proper divisors (1).

811897 is an equidigital number, since it uses as much as digits as its factorization.

811897 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4032, while the sum is 34.

The square root of 811897 is about 901.0532725649. The cubic root of 811897 is about 93.2896890615.

The spelling of 811897 in words is "eight hundred eleven thousand, eight hundred ninety-seven".