111100129981 has 2 divisors, whose sum is σ = 111100129982. Its totient is φ = 111100129980.

The previous prime is 111100129969. The next prime is 111100130021. The reversal of 111100129981 is 189921001111.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 88821880900 + 22278249081 = 298030^2 + 149259^2 .

It is a cyclic number.

It is not a de Polignac number, because 111100129981 - 2⁷ = 111100129853 is a prime.

It is a super-2 number, since 2×111100129981² (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 (111100129781) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 55550064990 + 55550064991.

It is an arithmetic number, because the mean of its divisors is an integer number (55550064991).

Almost surely, 2^111100129981 is an apocalyptic number.

It is an amenable number.

111100129981 is a deficient number, since it is larger than the sum of its proper divisors (1).

111100129981 is an equidigital number, since it uses as much as digits as its factorization.

111100129981 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1296, while the sum is 34.

It can be divided in two parts, 111100 and 129981, that added together give a square (241081 = 491²).

The spelling of 111100129981 in words is "one hundred eleven billion, one hundred million, one hundred twenty-nine thousand, nine hundred eighty-one".