811911197 has 2 divisors, whose sum is σ = 811911198. Its totient is φ = 811911196.

The previous prime is 811911179. The next prime is 811911223. The reversal of 811911197 is 791119118.

It is a happy number.

Together with previous prime (811911179) 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., 807184921 + 4726276 = 28411^2 + 2174^2 .

It is a cyclic number.

It is not a de Polignac number, because 811911197 - 2¹⁴ = 811894813 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 811911197.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (811911697) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 405955598 + 405955599.

It is an arithmetic number, because the mean of its divisors is an integer number (405955599).

Almost surely, 2^811911197 is an apocalyptic number.

It is an amenable number.

811911197 is a deficient number, since it is larger than the sum of its proper divisors (1).

811911197 is an equidigital number, since it uses as much as digits as its factorization.

811911197 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4536, while the sum is 38.

The square root of 811911197 is about 28494.0554677638. The cubic root of 811911197 is about 932.9023281930.

The spelling of 811911197 in words is "eight hundred eleven million, nine hundred eleven thousand, one hundred ninety-seven".