2011085981 has 2 divisors, whose sum is σ = 2011085982. Its totient is φ = 2011085980.

The previous prime is 2011085969. The next prime is 2011086001. The reversal of 2011085981 is 1895801102.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1724325625 + 286760356 = 41525^2 + 16934^2 .

It is a cyclic number.

It is not a de Polignac number, because 2011085981 - 2⁶ = 2011085917 is a prime.

It is a super-2 number, since 2×2011085981² = 8088933645949464722, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2011085081) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1005542990 + 1005542991.

It is an arithmetic number, because the mean of its divisors is an integer number (1005542991).

Almost surely, 2^2011085981 is an apocalyptic number.

It is an amenable number.

2011085981 is a deficient number, since it is larger than the sum of its proper divisors (1).

2011085981 is an equidigital number, since it uses as much as digits as its factorization.

2011085981 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5760, while the sum is 35.

The square root of 2011085981 is about 44845.1333034032. The cubic root of 2011085981 is about 1262.2446720336.

The spelling of 2011085981 in words is "two billion, eleven million, eighty-five thousand, nine hundred eighty-one".