1231243231 has 4 divisors (see below), whose sum is σ = 1232687512. Its totient is φ = 1229798952.

The previous prime is 1231243217. The next prime is 1231243253. The reversal of 1231243231 is 1323421321.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1323421321 = 17 ⋅77848313.

It is a cyclic number.

It is not a de Polignac number, because 1231243231 - 2⁷ = 1231243103 is a prime.

It is a super-2 number, since 2×1231243231² = 3031919787766638722, 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 (1231243201) 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, 720861 + ... + 722566.

It is an arithmetic number, because the mean of its divisors is an integer number (308171878).

Almost surely, 2^1231243231 is an apocalyptic number.

1231243231 is a deficient number, since it is larger than the sum of its proper divisors (1444281).

1231243231 is an equidigital number, since it uses as much as digits as its factorization.

1231243231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1444280.

The product of its digits is 864, while the sum is 22.

The square root of 1231243231 is about 35089.0756646567. The cubic root of 1231243231 is about 1071.8021370242.

Adding to 1231243231 its reverse (1323421321), we get a palindrome (2554664552).

The spelling of 1231243231 in words is "one billion, two hundred thirty-one million, two hundred forty-three thousand, two hundred thirty-one".