778494494857 has 2 divisors, whose sum is σ = 778494494858. Its totient is φ = 778494494856.

The previous prime is 778494494803. The next prime is 778494494863. The reversal of 778494494857 is 758494494877.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 554065854736 + 224428640121 = 744356^2 + 473739^2 .

It is a cyclic number.

It is not a de Polignac number, because 778494494857 - 2¹⁵ = 778494462089 is a prime.

It is not a weakly prime, because it can be changed into another prime (778494491857) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 389247247428 + 389247247429.

It is an arithmetic number, because the mean of its divisors is an integer number (389247247429).

Almost surely, 2^778494494857 is an apocalyptic number.

It is an amenable number.

778494494857 is a deficient number, since it is larger than the sum of its proper divisors (1).

778494494857 is an equidigital number, since it uses as much as digits as its factorization.

778494494857 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2275983360, while the sum is 76.

The spelling of 778494494857 in words is "seven hundred seventy-eight billion, four hundred ninety-four million, four hundred ninety-four thousand, eight hundred fifty-seven".