111111010981 has 2 divisors, whose sum is σ = 111111010982. Its totient is φ = 111111010980.

The previous prime is 111111010973. The next prime is 111111010999. The reversal of 111111010981 is 189010111111.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 79180894881 + 31930116100 = 281391^2 + 178690^2 .

It is a cyclic number.

It is not a de Polignac number, because 111111010981 - 2³ = 111111010973 is a prime.

It is a super-2 number, since 2×111111010981² (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 (111111010781) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 55555505490 + 55555505491.

It is an arithmetic number, because the mean of its divisors is an integer number (55555505491).

Almost surely, 2^111111010981 is an apocalyptic number.

It is an amenable number.

111111010981 is a deficient number, since it is larger than the sum of its proper divisors (1).

111111010981 is an equidigital number, since it uses as much as digits as its factorization.

111111010981 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 72, while the sum is 25.

The spelling of 111111010981 in words is "one hundred eleven billion, one hundred eleven million, ten thousand, nine hundred eighty-one".