778871 has 2 divisors, whose sum is σ = 778872. Its totient is φ = 778870.

The previous prime is 778847. The next prime is 778873. The reversal of 778871 is 178877.

It is a strong prime.

It is an emirp because it is prime and its reverse (178877) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 778871 - 2¹⁸ = 516727 is a prime.

Together with 778873, it forms a pair of twin primes.

It is a Chen prime.

It is an Ulam number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (778873) 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, 389435 + 389436.

It is an arithmetic number, because the mean of its divisors is an integer number (389436).

2⁷⁷⁸⁸⁷¹ is an apocalyptic number.

778871 is a deficient number, since it is larger than the sum of its proper divisors (1).

778871 is an equidigital number, since it uses as much as digits as its factorization.

778871 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 21952, while the sum is 38.

The square root of 778871 is about 882.5366847899. The cubic root of 778871 is about 92.0072064298.

The spelling of 778871 in words is "seven hundred seventy-eight thousand, eight hundred seventy-one".