100111010999981 has 2 divisors, whose sum is σ = 100111010999982. Its totient is φ = 100111010999980.

The previous prime is 100111010999971. The next prime is 100111011000001. The reversal of 100111010999981 is 189999010111001.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 99786414169225 + 324596830756 = 9989315^2 + 569734^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-100111010999981 is a prime.

It is a super-2 number, since 2×100111010999981² (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 (100111010999971) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 50055505499990 + 50055505499991.

It is an arithmetic number, because the mean of its divisors is an integer number (50055505499991).

Almost surely, 2^{100111010999981} is an apocalyptic number.

It is an amenable number.

100111010999981 is a deficient number, since it is larger than the sum of its proper divisors (1).

100111010999981 is an equidigital number, since it uses as much as digits as its factorization.

100111010999981 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 52488, while the sum is 50.

The spelling of 100111010999981 in words is "one hundred trillion, one hundred eleven billion, ten million, nine hundred ninety-nine thousand, nine hundred eighty-one".