855889817 has 2 divisors, whose sum is σ = 855889818. Its totient is φ = 855889816.

The previous prime is 855889799. The next prime is 855889829. The reversal of 855889817 is 718988558.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 458645056 + 397244761 = 21416^2 + 19931^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-855889817 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (855889117) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 427944908 + 427944909.

It is an arithmetic number, because the mean of its divisors is an integer number (427944909).

Almost surely, 2^855889817 is an apocalyptic number.

It is an amenable number.

855889817 is a deficient number, since it is larger than the sum of its proper divisors (1).

855889817 is an equidigital number, since it uses as much as digits as its factorization.

855889817 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6451200, while the sum is 59.

The square root of 855889817 is about 29255.5946273529. The cubic root of 855889817 is about 949.4511389131.

The spelling of 855889817 in words is "eight hundred fifty-five million, eight hundred eighty-nine thousand, eight hundred seventeen".