1281116839 has 4 divisors (see below), whose sum is σ = 1281384720. Its totient is φ = 1280848960.

The previous prime is 1281116803. The next prime is 1281116843. The reversal of 1281116839 is 9386111821.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 9386111821 = 269 ⋅34892609.

It is a cyclic number.

It is not a de Polignac number, because 1281116839 - 2¹⁵ = 1281084071 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1281110839) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 126634 + ... + 136375.

It is an arithmetic number, because the mean of its divisors is an integer number (320346180).

Almost surely, 2^1281116839 is an apocalyptic number.

1281116839 is a deficient number, since it is larger than the sum of its proper divisors (267881).

1281116839 is an equidigital number, since it uses as much as digits as its factorization.

1281116839 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 267880.

The product of its digits is 20736, while the sum is 40.

The square root of 1281116839 is about 35792.6925363265. The cubic root of 1281116839 is about 1086.0827431142.

The spelling of 1281116839 in words is "one billion, two hundred eighty-one million, one hundred sixteen thousand, eight hundred thirty-nine".