111231323531 has 2 divisors, whose sum is σ = 111231323532. Its totient is φ = 111231323530.

The previous prime is 111231323513. The next prime is 111231323537. The reversal of 111231323531 is 135323132111.

Together with previous prime (111231323513) 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 (135323132111) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-111231323531 is a prime.

It is a super-2 number, since 2×111231323531² (a number of 23 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 111231323531.

It is not a weakly prime, because it can be changed into another prime (111231323537) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 55615661765 + 55615661766.

It is an arithmetic number, because the mean of its divisors is an integer number (55615661766).

Almost surely, 2^111231323531 is an apocalyptic number.

111231323531 is a deficient number, since it is larger than the sum of its proper divisors (1).

111231323531 is an equidigital number, since it uses as much as digits as its factorization.

111231323531 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1620, while the sum is 26.

Adding to 111231323531 its reverse (135323132111), we get a palindrome (246554455642).

The spelling of 111231323531 in words is "one hundred eleven billion, two hundred thirty-one million, three hundred twenty-three thousand, five hundred thirty-one".