1231142389 has 2 divisors, whose sum is σ = 1231142390. Its totient is φ = 1231142388.

The previous prime is 1231142387. The next prime is 1231142447. The reversal of 1231142389 is 9832411321.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 796086225 + 435056164 = 28215^2 + 20858^2 .

It is a cyclic number.

It is not a de Polignac number, because 1231142389 - 2¹ = 1231142387 is a prime.

Together with 1231142387, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1231142387) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 615571194 + 615571195.

It is an arithmetic number, because the mean of its divisors is an integer number (615571195).

Almost surely, 2^1231142389 is an apocalyptic number.

It is an amenable number.

1231142389 is a deficient number, since it is larger than the sum of its proper divisors (1).

1231142389 is an equidigital number, since it uses as much as digits as its factorization.

1231142389 is an evil number, because the sum of its binary digits is even.

The product of its digits is 10368, while the sum is 34.

The square root of 1231142389 is about 35087.6386922802. The cubic root of 1231142389 is about 1071.7728751044.

The spelling of 1231142389 in words is "one billion, two hundred thirty-one million, one hundred forty-two thousand, three hundred eighty-nine".