2778765139 has 2 divisors, whose sum is σ = 2778765140. Its totient is φ = 2778765138.

The previous prime is 2778765131. The next prime is 2778765211. The reversal of 2778765139 is 9315678772.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 2778765139 - 2³ = 2778765131 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 2778765139.

It is not a weakly prime, because it can be changed into another prime (2778765131) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1389382569 + 1389382570.

It is an arithmetic number, because the mean of its divisors is an integer number (1389382570).

Almost surely, 2^2778765139 is an apocalyptic number.

2778765139 is a deficient number, since it is larger than the sum of its proper divisors (1).

2778765139 is an equidigital number, since it uses as much as digits as its factorization.

2778765139 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4445280, while the sum is 55.

The square root of 2778765139 is about 52713.9937682585. The cubic root of 2778765139 is about 1405.8876436477.

The spelling of 2778765139 in words is "two billion, seven hundred seventy-eight million, seven hundred sixty-five thousand, one hundred thirty-nine".