678889018 has 4 divisors (see below), whose sum is σ = 1018333530. Its totient is φ = 339444508.

The previous prime is 678888997. The next prime is 678889021. The reversal of 678889018 is 810988876.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 424071649 + 254817369 = 20593^2 + 15963^2 .

It is a super-2 number, since 2×678889018² = 921780597522008648, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 678889018.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 169722253 + ... + 169722256.

Almost surely, 2^678889018 is an apocalyptic number.

678889018 is a deficient number, since it is larger than the sum of its proper divisors (339444512).

678889018 is a wasteful number, since it uses less digits than its factorization.

678889018 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 339444511.

The product of its (nonzero) digits is 1548288, while the sum is 55.

The square root of 678889018 is about 26055.4988054345. The cubic root of 678889018 is about 878.8867715594.

The spelling of 678889018 in words is "six hundred seventy-eight million, eight hundred eighty-nine thousand, eighteen".