100109999981 has 2 divisors, whose sum is σ = 100109999982. Its totient is φ = 100109999980.

The previous prime is 100109999923. The next prime is 100110000007. The reversal of 100109999981 is 189999901001.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 83010253225 + 17099746756 = 288115^2 + 130766^2 .

It is an emirp because it is prime and its reverse (189999901001) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 100109999981 - 2¹⁰ = 100109998957 is a prime.

It is a super-2 number, since 2×100109999981² (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 (100109999911) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 50054999990 + 50054999991.

It is an arithmetic number, because the mean of its divisors is an integer number (50054999991).

Almost surely, 2^100109999981 is an apocalyptic number.

It is an amenable number.

100109999981 is a deficient number, since it is larger than the sum of its proper divisors (1).

100109999981 is an equidigital number, since it uses as much as digits as its factorization.

100109999981 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 472392, while the sum is 56.

The spelling of 100109999981 in words is "one hundred billion, one hundred nine million, nine hundred ninety-nine thousand, nine hundred eighty-one".