778981873 has 2 divisors, whose sum is σ = 778981874. Its totient is φ = 778981872.

The previous prime is 778981867. The next prime is 778981883. The reversal of 778981873 is 378189877.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 775511104 + 3470769 = 27848^2 + 1863^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-778981873 is a prime.

It is not a weakly prime, because it can be changed into another prime (778981843) 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, 389490936 + 389490937.

It is an arithmetic number, because the mean of its divisors is an integer number (389490937).

Almost surely, 2^778981873 is an apocalyptic number.

It is an amenable number.

778981873 is a deficient number, since it is larger than the sum of its proper divisors (1).

778981873 is an equidigital number, since it uses as much as digits as its factorization.

778981873 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4741632, while the sum is 58.

The square root of 778981873 is about 27910.2467384292. The cubic root of 778981873 is about 920.1157199271.

The spelling of 778981873 in words is "seven hundred seventy-eight million, nine hundred eighty-one thousand, eight hundred seventy-three".