855889861 has 2 divisors, whose sum is σ = 855889862. Its totient is φ = 855889860.

The previous prime is 855889849. The next prime is 855889873. The reversal of 855889861 is 168988558.

It is a balanced prime because it is at equal distance from previous prime (855889849) and next prime (855889873).

It can be written as a sum of positive squares in only one way, i.e., 689325025 + 166564836 = 26255^2 + 12906^2 .

It is a cyclic number.

It is not a de Polignac number, because 855889861 - 2⁵ = 855889829 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 855889796 and 855889805.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (855881861) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 427944930 + 427944931.

It is an arithmetic number, because the mean of its divisors is an integer number (427944931).

Almost surely, 2^855889861 is an apocalyptic number.

855889861 is the 13084-th centered decagonal number.

It is an amenable number.

855889861 is a deficient number, since it is larger than the sum of its proper divisors (1).

855889861 is an equidigital number, since it uses as much as digits as its factorization.

855889861 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5529600, while the sum is 58.

The square root of 855889861 is about 29255.5953793458. The cubic root of 855889861 is about 949.4511551830.

The spelling of 855889861 in words is "eight hundred fifty-five million, eight hundred eighty-nine thousand, eight hundred sixty-one".