85051685981 has 2 divisors, whose sum is σ = 85051685982. Its totient is φ = 85051685980.

The previous prime is 85051685977. The next prime is 85051685989. The reversal of 85051685981 is 18958615058.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 73416612025 + 11635073956 = 270955^2 + 107866^2 .

It is a cyclic number.

It is not a de Polignac number, because 85051685981 - 2² = 85051685977 is a prime.

It is a super-2 number, since 2×85051685981² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (85051685989) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 42525842990 + 42525842991.

It is an arithmetic number, because the mean of its divisors is an integer number (42525842991).

Almost surely, 2^85051685981 is an apocalyptic number.

It is an amenable number.

85051685981 is a deficient number, since it is larger than the sum of its proper divisors (1).

85051685981 is an equidigital number, since it uses as much as digits as its factorization.

85051685981 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3456000, while the sum is 56.

The spelling of 85051685981 in words is "eighty-five billion, fifty-one million, six hundred eighty-five thousand, nine hundred eighty-one".