1279934989 has 2 divisors, whose sum is σ = 1279934990. Its totient is φ = 1279934988.

The previous prime is 1279934987. The next prime is 1279934993. The reversal of 1279934989 is 9894399721.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 724955625 + 554979364 = 26925^2 + 23558^2 .

It is a cyclic number.

It is not a de Polignac number, because 1279934989 - 2¹ = 1279934987 is a prime.

Together with 1279934987, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1279934987) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 639967494 + 639967495.

It is an arithmetic number, because the mean of its divisors is an integer number (639967495).

Almost surely, 2^1279934989 is an apocalyptic number.

It is an amenable number.

1279934989 is a deficient number, since it is larger than the sum of its proper divisors (1).

1279934989 is an equidigital number, since it uses as much as digits as its factorization.

1279934989 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 8817984, while the sum is 61.

The square root of 1279934989 is about 35776.1790721145. The cubic root of 1279934989 is about 1085.7486643472.

The spelling of 1279934989 in words is "one billion, two hundred seventy-nine million, nine hundred thirty-four thousand, nine hundred eighty-nine".