77663643808 has 12 divisors (see below), whose sum is σ = 152900298810. Its totient is φ = 38831821888.

The previous prime is 77663643797. The next prime is 77663643809. The reversal of 77663643808 is 80834636677.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 41376441744 + 36287202064 = 203412^2 + 190492^2 .

It is not an unprimeable number, because it can be changed into a prime (77663643809) 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, 1213494403 + ... + 1213494466.

Almost surely, 2^77663643808 is an apocalyptic number.

It is an amenable number.

77663643808 is a deficient number, since it is larger than the sum of its proper divisors (75236655002).

77663643808 is a wasteful number, since it uses less digits than its factorization.

77663643808 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2426988879 (or 2426988871 counting only the distinct ones).

The product of its (nonzero) digits is 24385536, while the sum is 58.

The spelling of 77663643808 in words is "seventy-seven billion, six hundred sixty-three million, six hundred forty-three thousand, eight hundred eight".