778981867 has 2 divisors, whose sum is σ = 778981868. Its totient is φ = 778981866.

The previous prime is 778981843. The next prime is 778981873. The reversal of 778981867 is 768189877.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 778981867 - 2⁷ = 778981739 is a prime.

It is a super-2 number, since 2×778981867² = 1213625498229611378, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (778981067) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 389490933 + 389490934.

It is an arithmetic number, because the mean of its divisors is an integer number (389490934).

Almost surely, 2^778981867 is an apocalyptic number.

778981867 is a deficient number, since it is larger than the sum of its proper divisors (1).

778981867 is an equidigital number, since it uses as much as digits as its factorization.

778981867 is an evil number, because the sum of its binary digits is even.

The product of its digits is 9483264, while the sum is 61.

The square root of 778981867 is about 27910.2466309418. The cubic root of 778981867 is about 920.1157175648.

The spelling of 778981867 in words is "seven hundred seventy-eight million, nine hundred eighty-one thousand, eight hundred sixty-seven".