778216469 has 2 divisors, whose sum is σ = 778216470. Its totient is φ = 778216468.

The previous prime is 778216441. The next prime is 778216507. The reversal of 778216469 is 964612877.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 628153969 + 150062500 = 25063^2 + 12250^2 .

It is a cyclic number.

It is not a de Polignac number, because 778216469 - 2²⁴ = 761439253 is a prime.

It is a super-2 number, since 2×778216469² = 1211241745245655922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (778216409) 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, 389108234 + 389108235.

It is an arithmetic number, because the mean of its divisors is an integer number (389108235).

Almost surely, 2^778216469 is an apocalyptic number.

It is an amenable number.

778216469 is a deficient number, since it is larger than the sum of its proper divisors (1).

778216469 is an equidigital number, since it uses as much as digits as its factorization.

778216469 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1016064, while the sum is 50.

The square root of 778216469 is about 27896.5314869071. The cubic root of 778216469 is about 919.8142618896.

The spelling of 778216469 in words is "seven hundred seventy-eight million, two hundred sixteen thousand, four hundred sixty-nine".