11111531 has 2 divisors, whose sum is σ = 11111532. Its totient is φ = 11111530.

The previous prime is 11111509. The next prime is 11111579. The reversal of 11111531 is 13511111.

11111531 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 11111531 - 2¹⁸ = 10849387 is a prime.

It is a super-2 number, since 2×11111531² = 246932242327922, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (11111131) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5555765 + 5555766.

It is an arithmetic number, because the mean of its divisors is an integer number (5555766).

Almost surely, 2^11111531 is an apocalyptic number.

11111531 is a deficient number, since it is larger than the sum of its proper divisors (1).

11111531 is an equidigital number, since it uses as much as digits as its factorization.

11111531 is an evil number, because the sum of its binary digits is even.

The product of its digits is 15, while the sum is 14.

The square root of 11111531 is about 3333.3963160716. The cubic root of 11111531 is about 223.1471275332.

Adding to 11111531 its reverse (13511111), we get a palindrome (24622642).

The spelling of 11111531 in words is "eleven million, one hundred eleven thousand, five hundred thirty-one".