1288985809 has 2 divisors, whose sum is σ = 1288985810. Its totient is φ = 1288985808.

The previous prime is 1288985807. The next prime is 1288985833. The reversal of 1288985809 is 9085898821.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 940342225 + 348643584 = 30665^2 + 18672^2 .

It is a cyclic number.

It is not a de Polignac number, because 1288985809 - 2¹ = 1288985807 is a prime.

It is a super-2 number, since 2×1288985809² = 3322968831606768962, which contains 22 as substring.

Together with 1288985807, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (1288985801) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 644492904 + 644492905.

It is an arithmetic number, because the mean of its divisors is an integer number (644492905).

Almost surely, 2^1288985809 is an apocalyptic number.

It is an amenable number.

1288985809 is a deficient number, since it is larger than the sum of its proper divisors (1).

1288985809 is an equidigital number, since it uses as much as digits as its factorization.

1288985809 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 3317760, while the sum is 58.

The square root of 1288985809 is about 35902.4485098162. The cubic root of 1288985809 is about 1088.3018781997.

The spelling of 1288985809 in words is "one billion, two hundred eighty-eight million, nine hundred eighty-five thousand, eight hundred nine".