100000999999981 has 2 divisors, whose sum is σ = 100000999999982. Its totient is φ = 100000999999980.

The previous prime is 100000999999937. The next prime is 100001000000059. The reversal of 100000999999981 is 189999999000001.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 99705537090756 + 295462909225 = 9985266^2 + 543565^2 .

It is a cyclic number.

It is not a de Polignac number, because 100000999999981 - 2¹⁹ = 100000999475693 is a prime.

It is a super-2 number, since 2×100000999999981² (a number of 29 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (100000999996981) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 50000499999990 + 50000499999991.

It is an arithmetic number, because the mean of its divisors is an integer number (50000499999991).

Almost surely, 2^{100000999999981} is an apocalyptic number.

It is an amenable number.

100000999999981 is a deficient number, since it is larger than the sum of its proper divisors (1).

100000999999981 is an equidigital number, since it uses as much as digits as its factorization.

100000999999981 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 38263752, while the sum is 73.

The spelling of 100000999999981 in words is "one hundred trillion, nine hundred ninety-nine million, nine hundred ninety-nine thousand, nine hundred eighty-one".