778016891 has 2 divisors, whose sum is σ = 778016892. Its totient is φ = 778016890.

The previous prime is 778016867. The next prime is 778016903. The reversal of 778016891 is 198610877.

It is a strong prime.

It is an emirp because it is prime and its reverse (198610877) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-778016891 is a prime.

It is not a weakly prime, because it can be changed into another prime (778016801) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 389008445 + 389008446.

It is an arithmetic number, because the mean of its divisors is an integer number (389008446).

Almost surely, 2^778016891 is an apocalyptic number.

778016891 is a deficient number, since it is larger than the sum of its proper divisors (1).

778016891 is an equidigital number, since it uses as much as digits as its factorization.

778016891 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 169344, while the sum is 47.

The square root of 778016891 is about 27892.9541461639. The cubic root of 778016891 is about 919.7356246496.

The spelling of 778016891 in words is "seven hundred seventy-eight million, sixteen thousand, eight hundred ninety-one".