1287752491 has 2 divisors, whose sum is σ = 1287752492. Its totient is φ = 1287752490.

The previous prime is 1287752443. The next prime is 1287752507. The reversal of 1287752491 is 1942577821.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1287752491 - 2⁹ = 1287751979 is a prime.

It is not a weakly prime, because it can be changed into another prime (1287759491) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 643876245 + 643876246.

It is an arithmetic number, because the mean of its divisors is an integer number (643876246).

Almost surely, 2^1287752491 is an apocalyptic number.

1287752491 is a deficient number, since it is larger than the sum of its proper divisors (1).

1287752491 is an equidigital number, since it uses as much as digits as its factorization.

1287752491 is an evil number, because the sum of its binary digits is even.

The product of its digits is 282240, while the sum is 46.

The square root of 1287752491 is about 35885.2684398487. The cubic root of 1287752491 is about 1087.9546670824.

The spelling of 1287752491 in words is "one billion, two hundred eighty-seven million, seven hundred fifty-two thousand, four hundred ninety-one".