663868678 has 12 divisors (see below), whose sum is σ = 1094560740. Its totient is φ = 301758380.

The previous prime is 663868669. The next prime is 663868687. The reversal of 663868678 is 876868366.

It is an interprime number because it is at equal distance from previous prime (663868669) and next prime (663868687).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1371388 + ... + 1371871.

It is an arithmetic number, because the mean of its divisors is an integer number (91213395).

Almost surely, 2^663868678 is an apocalyptic number.

663868678 is a deficient number, since it is larger than the sum of its proper divisors (430692062).

663868678 is a wasteful number, since it uses less digits than its factorization.

663868678 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2743283 (or 2743272 counting only the distinct ones).

The product of its digits is 13934592, while the sum is 58.

The square root of 663868678 is about 25765.6491864653. The cubic root of 663868678 is about 872.3566168600.

The spelling of 663868678 in words is "six hundred sixty-three million, eight hundred sixty-eight thousand, six hundred seventy-eight".