1287286391 has 2 divisors, whose sum is σ = 1287286392. Its totient is φ = 1287286390.

The previous prime is 1287286331. The next prime is 1287286411. The reversal of 1287286391 is 1936827821.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1287286391 - 2¹⁸ = 1287024247 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1287286331) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 643643195 + 643643196.

It is an arithmetic number, because the mean of its divisors is an integer number (643643196).

Almost surely, 2^1287286391 is an apocalyptic number.

1287286391 is a deficient number, since it is larger than the sum of its proper divisors (1).

1287286391 is an equidigital number, since it uses as much as digits as its factorization.

1287286391 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 290304, while the sum is 47.

The square root of 1287286391 is about 35878.7735436985. The cubic root of 1287286391 is about 1087.8233900792.

The spelling of 1287286391 in words is "one billion, two hundred eighty-seven million, two hundred eighty-six thousand, three hundred ninety-one".