111111111100081 has 2 divisors, whose sum is σ = 111111111100082. Its totient is φ = 111111111100080.

The previous prime is 111111111100027. The next prime is 111111111100097. The reversal of 111111111100081 is 180001111111111.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 70368945504400 + 40742165595681 = 8388620^2 + 6382959^2 .

It is an emirp because it is prime and its reverse (180001111111111) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 111111111100081 - 2³⁷ = 110973672146609 is a prime.

It is a super-2 number, since 2×111111111100081² (a number of 29 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (111111111100021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 55555555550040 + 55555555550041.

It is an arithmetic number, because the mean of its divisors is an integer number (55555555550041).

Almost surely, 2^{111111111100081} is an apocalyptic number.

It is an amenable number.

111111111100081 is a deficient number, since it is larger than the sum of its proper divisors (1).

111111111100081 is an equidigital number, since it uses as much as digits as its factorization.

111111111100081 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8, while the sum is 19.

Adding to 111111111100081 its reverse (180001111111111), we get a palindrome (291112222211192).

The spelling of 111111111100081 in words is "one hundred eleven trillion, one hundred eleven billion, one hundred eleven million, one hundred thousand, eighty-one".