856260389 has 2 divisors, whose sum is σ = 856260390. Its totient is φ = 856260388.

The previous prime is 856260341. The next prime is 856260397. The reversal of 856260389 is 983062658.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 721352164 + 134908225 = 26858^2 + 11615^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-856260389 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (856260089) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 428130194 + 428130195.

It is an arithmetic number, because the mean of its divisors is an integer number (428130195).

Almost surely, 2^856260389 is an apocalyptic number.

It is an amenable number.

856260389 is a deficient number, since it is larger than the sum of its proper divisors (1).

856260389 is an equidigital number, since it uses as much as digits as its factorization.

856260389 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 622080, while the sum is 47.

The square root of 856260389 is about 29261.9272946947. The cubic root of 856260389 is about 949.5881461284.

The spelling of 856260389 in words is "eight hundred fifty-six million, two hundred sixty thousand, three hundred eighty-nine".