131111111 has 2 divisors, whose sum is σ = 131111112. Its totient is φ = 131111110.

The previous prime is 131111107. The next prime is 131111119. The reversal of 131111111 is 111111131.

It is a weak prime.

It is an emirp because it is prime and its reverse (111111131) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 131111111 - 2² = 131111107 is a prime.

131111111 is a modest number, since divided by 11111 gives 1311 as remainder.

It is a junction number, because it is equal to n+sod(n) for n = 131111092 and 131111101.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (131111119) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 65555555 + 65555556.

It is an arithmetic number, because the mean of its divisors is an integer number (65555556).

Almost surely, 2^131111111 is an apocalyptic number.

131111111 is a deficient number, since it is larger than the sum of its proper divisors (1).

131111111 is an equidigital number, since it uses as much as digits as its factorization.

131111111 is an evil number, because the sum of its binary digits is even.

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

The square root of 131111111 is about 11450.3760200266. The cubic root of 131111111 is about 508.0188563794.

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

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

The spelling of 131111111 in words is "one hundred thirty-one million, one hundred eleven thousand, one hundred eleven".