1287440291 has 2 divisors, whose sum is σ = 1287440292. Its totient is φ = 1287440290.

The previous prime is 1287440279. The next prime is 1287440299. The reversal of 1287440291 is 1920447821.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1287440291 - 2³⁰ = 213698467 is a prime.

It is not a weakly prime, because it can be changed into another prime (1287440299) 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 as a sum of consecutive naturals, namely, 643720145 + 643720146.

It is an arithmetic number, because the mean of its divisors is an integer number (643720146).

Almost surely, 2^1287440291 is an apocalyptic number.

1287440291 is a deficient number, since it is larger than the sum of its proper divisors (1).

1287440291 is an equidigital number, since it uses as much as digits as its factorization.

1287440291 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 32256, while the sum is 38.

The square root of 1287440291 is about 35880.9182017406. The cubic root of 1287440291 is about 1087.8667394975.

The spelling of 1287440291 in words is "one billion, two hundred eighty-seven million, four hundred forty thousand, two hundred ninety-one".