678856686418 has 8 divisors (see below), whose sum is σ = 1034978227020. Its totient is φ = 333863944080.

The previous prime is 678856686401. The next prime is 678856686419. The reversal of 678856686418 is 814686658876.

678856686418 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 667199813329 + 11656873089 = 816823^2 + 107967^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (678856686419) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2782199413 + ... + 2782199656.

Almost surely, 2^678856686418 is an apocalyptic number.

678856686418 is a deficient number, since it is larger than the sum of its proper divisors (356121540602).

678856686418 is a wasteful number, since it uses less digits than its factorization.

678856686418 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5564399132.

The product of its digits is 743178240, while the sum is 73.

The spelling of 678856686418 in words is "six hundred seventy-eight billion, eight hundred fifty-six million, six hundred eighty-six thousand, four hundred eighteen".