111111131 has 2 divisors, whose sum is σ = 111111132. Its totient is φ = 111111130.

The previous prime is 111111113. The next prime is 111111139. The reversal of 111111131 is 131111111.

Together with previous prime (111111113) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It is an emirp because it is prime and its reverse (131111111) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 111111131 - 2⁶ = 111111067 is a prime.

It is a super-2 number, since 2×111111131² = 24691366864198322, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (111111139) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 55555565 + 55555566.

It is an arithmetic number, because the mean of its divisors is an integer number (55555566).

Almost surely, 2^111111131 is an apocalyptic number.

111111131 is a deficient number, since it is larger than the sum of its proper divisors (1).

111111131 is an equidigital number, since it uses as much as digits as its factorization.

111111131 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3, while the sum is 11.

The square root of 111111131 is about 10540.9264773074. The cubic root of 111111131 is about 480.7498854539.

Adding to 111111131 its reverse (131111111), we get a palindrome (242222242).

It can be divided in two parts, 111111 and 131, that multiplied together give a palindrome (14555541).

The spelling of 111111131 in words is "one hundred eleven million, one hundred eleven thousand, one hundred thirty-one".