10081999981 has 2 divisors, whose sum is σ = 10081999982. Its totient is φ = 10081999980.

The previous prime is 10081999951. The next prime is 10082000041. The reversal of 10081999981 is 18999918001.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 9519124356 + 562875625 = 97566^2 + 23725^2 .

It is an emirp because it is prime and its reverse (18999918001) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 10081999981 - 2²⁵ = 10048445549 is a prime.

It is a super-2 number, since 2×10081999981² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (10081999951) 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, 5040999990 + 5040999991.

It is an arithmetic number, because the mean of its divisors is an integer number (5040999991).

Almost surely, 2^10081999981 is an apocalyptic number.

It is an amenable number.

10081999981 is a deficient number, since it is larger than the sum of its proper divisors (1).

10081999981 is an equidigital number, since it uses as much as digits as its factorization.

10081999981 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 419904, while the sum is 55.

The spelling of 10081999981 in words is "ten billion, eighty-one million, nine hundred ninety-nine thousand, nine hundred eighty-one".