855772817 has 2 divisors, whose sum is σ = 855772818. Its totient is φ = 855772816.

The previous prime is 855772811. The next prime is 855772831. The reversal of 855772817 is 718277558.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 584478976 + 271293841 = 24176^2 + 16471^2 .

It is a cyclic number.

It is not a de Polignac number, because 855772817 - 2²² = 851578513 is a prime.

It is a super-2 number, since 2×855772817² = 1464694228632230978, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (855772811) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 427886408 + 427886409.

It is an arithmetic number, because the mean of its divisors is an integer number (427886409).

Almost surely, 2^855772817 is an apocalyptic number.

It is an amenable number.

855772817 is a deficient number, since it is larger than the sum of its proper divisors (1).

855772817 is an equidigital number, since it uses as much as digits as its factorization.

855772817 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1097600, while the sum is 50.

The square root of 855772817 is about 29253.5949414769. The cubic root of 855772817 is about 949.4078736690.

The spelling of 855772817 in words is "eight hundred fifty-five million, seven hundred seventy-two thousand, eight hundred seventeen".