678138658 has 8 divisors (see below), whose sum is σ = 1020881052. Its totient is φ = 337844976.

The previous prime is 678138613. The next prime is 678138673. The reversal of 678138658 is 856831876.

It can be written as a sum of positive squares in 2 ways, for example, as 654489889 + 23648769 = 25583^2 + 4863^2 .

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 611485 + ... + 612592.

Almost surely, 2^678138658 is an apocalyptic number.

678138658 is a deficient number, since it is larger than the sum of its proper divisors (342742394).

678138658 is a wasteful number, since it uses less digits than its factorization.

678138658 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1224356.

The product of its digits is 1935360, while the sum is 52.

The square root of 678138658 is about 26041.0955606710. The cubic root of 678138658 is about 878.5628479236.

The spelling of 678138658 in words is "six hundred seventy-eight million, one hundred thirty-eight thousand, six hundred fifty-eight".