865534391 has 2 divisors, whose sum is σ = 865534392. Its totient is φ = 865534390.

The previous prime is 865534363. The next prime is 865534393. The reversal of 865534391 is 193435568.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 865534391 - 2¹⁴ = 865518007 is a prime.

Together with 865534393, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (865534393) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 432767195 + 432767196.

It is an arithmetic number, because the mean of its divisors is an integer number (432767196).

Almost surely, 2^865534391 is an apocalyptic number.

865534391 is a deficient number, since it is larger than the sum of its proper divisors (1).

865534391 is an equidigital number, since it uses as much as digits as its factorization.

865534391 is an evil number, because the sum of its binary digits is even.

The product of its digits is 388800, while the sum is 44.

The square root of 865534391 is about 29419.9658565404. The cubic root of 865534391 is about 953.0041157750.

The spelling of 865534391 in words is "eight hundred sixty-five million, five hundred thirty-four thousand, three hundred ninety-one".