11311111531 has 2 divisors, whose sum is σ = 11311111532. Its totient is φ = 11311111530.

The previous prime is 11311111463. The next prime is 11311111571. The reversal of 11311111531 is 13511111311.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 11311111531 - 2²⁵ = 11277557099 is a prime.

It is a super-2 number, since 2×11311111531² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 11311111499 and 11311111508.

It is not a weakly prime, because it can be changed into another prime (11311111571) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5655555765 + 5655555766.

It is an arithmetic number, because the mean of its divisors is an integer number (5655555766).

Almost surely, 2^11311111531 is an apocalyptic number.

11311111531 is a deficient number, since it is larger than the sum of its proper divisors (1).

11311111531 is an equidigital number, since it uses as much as digits as its factorization.

11311111531 is an evil number, because the sum of its binary digits is even.

The product of its digits is 45, while the sum is 19.

Adding to 11311111531 its reverse (13511111311), we get a palindrome (24822222842).

The spelling of 11311111531 in words is "eleven billion, three hundred eleven million, one hundred eleven thousand, five hundred thirty-one".