11581231 has 4 divisors (see below), whose sum is σ = 11739952. Its totient is φ = 11422512.

The previous prime is 11581177. The next prime is 11581249. The reversal of 11581231 is 13218511.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-11581231 is a prime.

It is a super-2 number, since 2×11581231² = 268249822950722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11581261) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 79251 + ... + 79396.

It is an arithmetic number, because the mean of its divisors is an integer number (2934988).

Almost surely, 2^11581231 is an apocalyptic number.

11581231 is a deficient number, since it is larger than the sum of its proper divisors (158721).

11581231 is an equidigital number, since it uses as much as digits as its factorization.

11581231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 158720.

The product of its digits is 240, while the sum is 22.

The square root of 11581231 is about 3403.1207736429. The cubic root of 11581231 is about 226.2480829686.

Adding to 11581231 its reverse (13218511), we get a palindrome (24799742).

The spelling of 11581231 in words is "eleven million, five hundred eighty-one thousand, two hundred thirty-one".