1231355143 has 2 divisors, whose sum is σ = 1231355144. Its totient is φ = 1231355142.

The previous prime is 1231355137. The next prime is 1231355149. The reversal of 1231355143 is 3415531321.

It is a happy number.

It is a balanced prime because it is at equal distance from previous prime (1231355137) and next prime (1231355149).

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1231355143 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1231355149) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 615677571 + 615677572.

It is an arithmetic number, because the mean of its divisors is an integer number (615677572).

Almost surely, 2^1231355143 is an apocalyptic number.

1231355143 is a deficient number, since it is larger than the sum of its proper divisors (1).

1231355143 is an equidigital number, since it uses as much as digits as its factorization.

1231355143 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5400, while the sum is 28.

The square root of 1231355143 is about 35090.6703127769. The cubic root of 1231355143 is about 1071.8346093210.

Adding to 1231355143 its reverse (3415531321), we get a palindrome (4646886464).

The spelling of 1231355143 in words is "one billion, two hundred thirty-one million, three hundred fifty-five thousand, one hundred forty-three".