985811881 has 2 divisors, whose sum is σ = 985811882. Its totient is φ = 985811880.

The previous prime is 985811857. The next prime is 985811921. The reversal of 985811881 is 188118589.

It is a happy number.

985811881 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 727920400 + 257891481 = 26980^2 + 16059^2 .

It is an emirp because it is prime and its reverse (188118589) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-985811881 is a prime.

It is a super-2 number, since 2×985811881² = 1943650129441516322, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (985811381) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 492905940 + 492905941.

It is an arithmetic number, because the mean of its divisors is an integer number (492905941).

Almost surely, 2^985811881 is an apocalyptic number.

It is an amenable number.

985811881 is a deficient number, since it is larger than the sum of its proper divisors (1).

985811881 is an equidigital number, since it uses as much as digits as its factorization.

985811881 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 184320, while the sum is 49.

The square root of 985811881 is about 31397.6413286094. The cubic root of 985811881 is about 995.2480820430.

The spelling of 985811881 in words is "nine hundred eighty-five million, eight hundred eleven thousand, eight hundred eighty-one".