865312191 has 6 divisors (see below), whose sum is σ = 1249895400. Its totient is φ = 576874788.

The previous prime is 865312171. The next prime is 865312199. The reversal of 865312191 is 191213568.

It is not a de Polignac number, because 865312191 - 2⁶ = 865312127 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (865312199) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 48072891 + ... + 48072908.

It is an arithmetic number, because the mean of its divisors is an integer number (208315900).

Almost surely, 2^865312191 is an apocalyptic number.

865312191 is a deficient number, since it is larger than the sum of its proper divisors (384583209).

865312191 is a wasteful number, since it uses less digits than its factorization.

865312191 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 96145805 (or 96145802 counting only the distinct ones).

The product of its digits is 12960, while the sum is 36.

The square root of 865312191 is about 29416.1892671366. The cubic root of 865312191 is about 952.9225570523.

The spelling of 865312191 in words is "eight hundred sixty-five million, three hundred twelve thousand, one hundred ninety-one".