678686672 has 20 divisors (see below), whose sum is σ = 1315828356. Its totient is φ = 339118080.

The previous prime is 678686651. The next prime is 678686711. The reversal of 678686672 is 276686876.

It can be written as a sum of positive squares in 2 ways, for example, as 366952336 + 311734336 = 19156^2 + 17656^2 .

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12272 + ... + 38832.

Almost surely, 2^678686672 is an apocalyptic number.

It is an amenable number.

678686672 is a deficient number, since it is larger than the sum of its proper divisors (637141684).

678686672 is a wasteful number, since it uses less digits than its factorization.

678686672 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28166 (or 28160 counting only the distinct ones).

The product of its digits is 8128512, while the sum is 56.

The square root of 678686672 is about 26051.6155353176. The cubic root of 678686672 is about 878.7994441321.

The spelling of 678686672 in words is "six hundred seventy-eight million, six hundred eighty-six thousand, six hundred seventy-two".