11531431 has 2 divisors, whose sum is σ = 11531432. Its totient is φ = 11531430.

The previous prime is 11531419. The next prime is 11531449. The reversal of 11531431 is 13413511.

It is a weak prime.

It is an emirp because it is prime and its reverse (13413511) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-11531431 is a prime.

It is a super-2 number, since 2×11531431² = 265947801815522, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 11531399 and 11531408.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (11531131) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5765715 + 5765716.

It is an arithmetic number, because the mean of its divisors is an integer number (5765716).

Almost surely, 2^11531431 is an apocalyptic number.

11531431 is a deficient number, since it is larger than the sum of its proper divisors (1).

11531431 is an equidigital number, since it uses as much as digits as its factorization.

11531431 is an evil number, because the sum of its binary digits is even.

The product of its digits is 180, while the sum is 19.

The square root of 11531431 is about 3395.7960775052. The cubic root of 11531431 is about 225.9233235068.

Adding to 11531431 its reverse (13413511), we get a palindrome (24944942).

The spelling of 11531431 in words is "eleven million, five hundred thirty-one thousand, four hundred thirty-one".