778819 has 2 divisors, whose sum is σ = 778820. Its totient is φ = 778818.

The previous prime is 778793. The next prime is 778831. The reversal of 778819 is 918877.

778819 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It is an emirp because it is prime and its reverse (918877) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 778819 - 2⁹ = 778307 is a prime.

It is a super-2 number, since 2×778819² = 1213118069522, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (778879) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 389409 + 389410.

It is an arithmetic number, because the mean of its divisors is an integer number (389410).

2⁷⁷⁸⁸¹⁹ is an apocalyptic number.

778819 is a deficient number, since it is larger than the sum of its proper divisors (1).

778819 is an equidigital number, since it uses as much as digits as its factorization.

778819 is an evil number, because the sum of its binary digits is even.

The product of its digits is 28224, while the sum is 40.

The square root of 778819 is about 882.5072237665. The cubic root of 778819 is about 92.0051588159.

The spelling of 778819 in words is "seven hundred seventy-eight thousand, eight hundred nineteen".