865905851 has 2 divisors, whose sum is σ = 865905852. Its totient is φ = 865905850.

The previous prime is 865905763. The next prime is 865905853. The reversal of 865905851 is 158509568.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 865905851 - 2²² = 861711547 is a prime.

Together with 865905853, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 865905796 and 865905805.

It is not a weakly prime, because it can be changed into another prime (865905853) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 432952925 + 432952926.

It is an arithmetic number, because the mean of its divisors is an integer number (432952926).

Almost surely, 2^865905851 is an apocalyptic number.

865905851 is a deficient number, since it is larger than the sum of its proper divisors (1).

865905851 is an equidigital number, since it uses as much as digits as its factorization.

865905851 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 432000, while the sum is 47.

The square root of 865905851 is about 29426.2782390162. The cubic root of 865905851 is about 953.1404293566.

The spelling of 865905851 in words is "eight hundred sixty-five million, nine hundred five thousand, eight hundred fifty-one".