678942218 has 4 divisors (see below), whose sum is σ = 1018413330. Its totient is φ = 339471108.

The previous prime is 678942109. The next prime is 678942223. The reversal of 678942218 is 812249876.

It is a happy number.

678942218 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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., 653671489 + 25270729 = 25567^2 + 5027^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 169735553 + ... + 169735556.

Almost surely, 2^678942218 is an apocalyptic number.

678942218 is a deficient number, since it is larger than the sum of its proper divisors (339471112).

678942218 is a wasteful number, since it uses less digits than its factorization.

678942218 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 339471111.

The product of its digits is 387072, while the sum is 47.

The square root of 678942218 is about 26056.5196831810. The cubic root of 678942218 is about 878.9097284560.

The spelling of 678942218 in words is "six hundred seventy-eight million, nine hundred forty-two thousand, two hundred eighteen".