1143257491 has 2 divisors, whose sum is σ = 1143257492. Its totient is φ = 1143257490.

The previous prime is 1143257483. The next prime is 1143257501. The reversal of 1143257491 is 1947523411.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1143257491 - 2³ = 1143257483 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1143257491.

It is not a weakly prime, because it can be changed into another prime (1143257441) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 571628745 + 571628746.

It is an arithmetic number, because the mean of its divisors is an integer number (571628746).

Almost surely, 2^1143257491 is an apocalyptic number.

1143257491 is a deficient number, since it is larger than the sum of its proper divisors (1).

1143257491 is an equidigital number, since it uses as much as digits as its factorization.

1143257491 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 30240, while the sum is 37.

The square root of 1143257491 is about 33812.0908995584. The cubic root of 1143257491 is about 1045.6379859172.

The spelling of 1143257491 in words is "one billion, one hundred forty-three million, two hundred fifty-seven thousand, four hundred ninety-one".