2778777161 has 2 divisors, whose sum is σ = 2778777162. Its totient is φ = 2778777160.

The previous prime is 2778777097. The next prime is 2778777191. The reversal of 2778777161 is 1617778772.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1902617161 + 876160000 = 43619^2 + 29600^2 .

It is a cyclic number.

It is not a de Polignac number, because 2778777161 - 2⁶ = 2778777097 is a prime.

It is not a weakly prime, because it can be changed into another prime (2778777191) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1389388580 + 1389388581.

It is an arithmetic number, because the mean of its divisors is an integer number (1389388581).

Almost surely, 2^2778777161 is an apocalyptic number.

It is an amenable number.

2778777161 is a deficient number, since it is larger than the sum of its proper divisors (1).

2778777161 is an equidigital number, since it uses as much as digits as its factorization.

2778777161 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1613472, while the sum is 53.

The square root of 2778777161 is about 52714.1077985770. The cubic root of 2778777161 is about 1405.8896711138.

The spelling of 2778777161 in words is "two billion, seven hundred seventy-eight million, seven hundred seventy-seven thousand, one hundred sixty-one".