1231331243 has 4 divisors (see below), whose sum is σ = 1284867408. Its totient is φ = 1177795080.

The previous prime is 1231331221. The next prime is 1231331263. The reversal of 1231331243 is 3421331321.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 3421331321 = 13309 ⋅257069.

It is a cyclic number.

It is not a de Polignac number, because 1231331243 - 2¹² = 1231327147 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (23), and also a Moran number because the ratio is a prime number: 53536141 = 1231331243 / (1 + 2 + 3 + 1 + 3 + 3 + 1 + 2 + 4 + 3).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1231331263) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 26768048 + ... + 26768093.

It is an arithmetic number, because the mean of its divisors is an integer number (321216852).

Almost surely, 2^1231331243 is an apocalyptic number.

1231331243 is a deficient number, since it is larger than the sum of its proper divisors (53536165).

1231331243 is an equidigital number, since it uses as much as digits as its factorization.

1231331243 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 53536164.

The product of its digits is 1296, while the sum is 23.

The square root of 1231331243 is about 35090.3297647657. The cubic root of 1231331243 is about 1071.8276746813.

Adding to 1231331243 its reverse (3421331321), we get a palindrome (4652662564).

The spelling of 1231331243 in words is "one billion, two hundred thirty-one million, three hundred thirty-one thousand, two hundred forty-three".