865655431 has 2 divisors, whose sum is σ = 865655432. Its totient is φ = 865655430.

The previous prime is 865655429. The next prime is 865655459. The reversal of 865655431 is 134556568.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 865655431 - 2¹ = 865655429 is a prime.

It is a super-2 number, since 2×865655431² = 1498718650439591522, which contains 22 as substring.

Together with 865655429, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (865655471) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 432827715 + 432827716.

It is an arithmetic number, because the mean of its divisors is an integer number (432827716).

Almost surely, 2^865655431 is an apocalyptic number.

865655431 is a deficient number, since it is larger than the sum of its proper divisors (1).

865655431 is an equidigital number, since it uses as much as digits as its factorization.

865655431 is an evil number, because the sum of its binary digits is even.

The product of its digits is 432000, while the sum is 43.

The square root of 865655431 is about 29422.0228910250. The cubic root of 865655431 is about 953.0485377501.

The spelling of 865655431 in words is "eight hundred sixty-five million, six hundred fifty-five thousand, four hundred thirty-one".