1320776689 has 2 divisors, whose sum is σ = 1320776690. Its totient is φ = 1320776688.

The previous prime is 1320776687. The next prime is 1320776701. The reversal of 1320776689 is 9866770231.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 958521600 + 362255089 = 30960^2 + 19033^2 .

It is an emirp because it is prime and its reverse (9866770231) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1320776689 - 2¹ = 1320776687 is a prime.

Together with 1320776687, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (1320776683) 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, 660388344 + 660388345.

It is an arithmetic number, because the mean of its divisors is an integer number (660388345).

Almost surely, 2^1320776689 is an apocalyptic number.

It is an amenable number.

1320776689 is a deficient number, since it is larger than the sum of its proper divisors (1).

1320776689 is an equidigital number, since it uses as much as digits as its factorization.

1320776689 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 762048, while the sum is 49.

The square root of 1320776689 is about 36342.4915078755. The cubic root of 1320776689 is about 1097.1764192574.

The spelling of 1320776689 in words is "one billion, three hundred twenty million, seven hundred seventy-six thousand, six hundred eighty-nine".