1287552391 has 2 divisors, whose sum is σ = 1287552392. Its totient is φ = 1287552390.

The previous prime is 1287552379. The next prime is 1287552401. The reversal of 1287552391 is 1932557821.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1287552391 - 2¹⁹ = 1287028103 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1287550391) 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, 643776195 + 643776196.

It is an arithmetic number, because the mean of its divisors is an integer number (643776196).

Almost surely, 2^1287552391 is an apocalyptic number.

1287552391 is a deficient number, since it is larger than the sum of its proper divisors (1).

1287552391 is an equidigital number, since it uses as much as digits as its factorization.

1287552391 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 151200, while the sum is 43.

The square root of 1287552391 is about 35882.4802793787. The cubic root of 1287552391 is about 1087.8983128251.

The spelling of 1287552391 in words is "one billion, two hundred eighty-seven million, five hundred fifty-two thousand, three hundred ninety-one".