865655491 has 2 divisors, whose sum is σ = 865655492. Its totient is φ = 865655490.

The previous prime is 865655471. The next prime is 865655537. The reversal of 865655491 is 194556568.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 865655491 - 2⁵ = 865655459 is a prime.

It is not a weakly prime, because it can be changed into another prime (865655431) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 432827745 + 432827746.

It is an arithmetic number, because the mean of its divisors is an integer number (432827746).

Almost surely, 2^865655491 is an apocalyptic number.

865655491 is a deficient number, since it is larger than the sum of its proper divisors (1).

865655491 is an equidigital number, since it uses as much as digits as its factorization.

865655491 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1296000, while the sum is 49.

The square root of 865655491 is about 29422.0239106694. The cubic root of 865655491 is about 953.0485597692.

The spelling of 865655491 in words is "eight hundred sixty-five million, six hundred fifty-five thousand, four hundred ninety-one".