985085861 has 2 divisors, whose sum is σ = 985085862. Its totient is φ = 985085860.

The previous prime is 985085819. The next prime is 985085863. The reversal of 985085861 is 168580589.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 718776100 + 266309761 = 26810^2 + 16319^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-985085861 is a prime.

It is a super-2 number, since 2×985085861² = 1940788307084222642, which contains 22 as substring.

Together with 985085863, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (985085863) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 492542930 + 492542931.

It is an arithmetic number, because the mean of its divisors is an integer number (492542931).

Almost surely, 2^985085861 is an apocalyptic number.

It is an amenable number.

985085861 is a deficient number, since it is larger than the sum of its proper divisors (1).

985085861 is an equidigital number, since it uses as much as digits as its factorization.

985085861 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 691200, while the sum is 50.

The square root of 985085861 is about 31386.0775026125. The cubic root of 985085861 is about 995.0036988827.

The spelling of 985085861 in words is "nine hundred eighty-five million, eighty-five thousand, eight hundred sixty-one".