778319873 has 2 divisors, whose sum is σ = 778319874. Its totient is φ = 778319872.

The previous prime is 778319849. The next prime is 778319887. The reversal of 778319873 is 378913877.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 747038224 + 31281649 = 27332^2 + 5593^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-778319873 is a prime.

It is a super-2 number, since 2×778319873² = 1211563649413472258, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (778319813) 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, 389159936 + 389159937.

It is an arithmetic number, because the mean of its divisors is an integer number (389159937).

Almost surely, 2^778319873 is an apocalyptic number.

It is an amenable number.

778319873 is a deficient number, since it is larger than the sum of its proper divisors (1).

778319873 is an equidigital number, since it uses as much as digits as its factorization.

778319873 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1778112, while the sum is 53.

The square root of 778319873 is about 27898.3847740331. The cubic root of 778319873 is about 919.8549995958.

The spelling of 778319873 in words is "seven hundred seventy-eight million, three hundred nineteen thousand, eight hundred seventy-three".