1131443231 has 4 divisors (see below), whose sum is σ = 1131517632. Its totient is φ = 1131368832.

The previous prime is 1131443227. The next prime is 1131443263. The reversal of 1131443231 is 1323441311.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 1323441311 = 313 ⋅4228247.

It is a cyclic number.

It is not a de Polignac number, because 1131443231 - 2² = 1131443227 is a prime.

It is a super-2 number, since 2×1131443231² = 2560327569951438722, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1131443197 and 1131443206.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1131443221) 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, 5231 + ... + 47856.

It is an arithmetic number, because the mean of its divisors is an integer number (282879408).

Almost surely, 2^1131443231 is an apocalyptic number.

1131443231 is a deficient number, since it is larger than the sum of its proper divisors (74401).

1131443231 is an equidigital number, since it uses as much as digits as its factorization.

1131443231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 74400.

The product of its digits is 864, while the sum is 23.

The square root of 1131443231 is about 33636.9325444518. The cubic root of 1131443231 is about 1042.0236826317.

Adding to 1131443231 its reverse (1323441311), we get a palindrome (2454884542).

It can be divided in two parts, 11314 and 43231, that added together give a palindrome (54545).

The spelling of 1131443231 in words is "one billion, one hundred thirty-one million, four hundred forty-three thousand, two hundred thirty-one".