816779 has 2 divisors, whose sum is σ = 816780. Its totient is φ = 816778.

The previous prime is 816769. The next prime is 816811. The reversal of 816779 is 977618.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 816779 - 2⁴ = 816763 is a prime.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (816709) 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, 408389 + 408390.

It is an arithmetic number, because the mean of its divisors is an integer number (408390).

2⁸¹⁶⁷⁷⁹ is an apocalyptic number.

816779 is a deficient number, since it is larger than the sum of its proper divisors (1).

816779 is an equidigital number, since it uses as much as digits as its factorization.

816779 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 21168, while the sum is 38.

The square root of 816779 is about 903.7582641393. The cubic root of 816779 is about 93.4763015806.

The spelling of 816779 in words is "eight hundred sixteen thousand, seven hundred seventy-nine".