111012100001981 has 2 divisors, whose sum is σ = 111012100001982. Its totient is φ = 111012100001980.

The previous prime is 111012100001951. The next prime is 111012100002029. The reversal of 111012100001981 is 189100001210111.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 110474604276100 + 537495725881 = 10510690^2 + 733141^2 .

It is a cyclic number.

It is not a de Polignac number, because 111012100001981 - 2⁴² = 106614053490877 is a prime.

It is a super-2 number, since 2×111012100001981² (a number of 29 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 111012100001981.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (111012100001951) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 55506050000990 + 55506050000991.

It is an arithmetic number, because the mean of its divisors is an integer number (55506050000991).

Almost surely, 2^{111012100001981} is an apocalyptic number.

It is an amenable number.

111012100001981 is a deficient number, since it is larger than the sum of its proper divisors (1).

111012100001981 is an equidigital number, since it uses as much as digits as its factorization.

111012100001981 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 144, while the sum is 26.

The spelling of 111012100001981 in words is "one hundred eleven trillion, twelve billion, one hundred million, one thousand, nine hundred eighty-one".