678999999 has 8 divisors (see below), whose sum is σ = 914123392. Its totient is φ = 448271640.

The previous prime is 678999949. The next prime is 679000019. The reversal of 678999999 is 999999876.

It is a happy number.

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

It is not a de Polignac number, because 678999999 - 2⁸ = 678999743 is a prime.

It is a super-2 number, since 2×678999999² = 922081997284000002, which contains 22 as substring.

It is a Duffinian number.

678999999 is a modest number, since divided by 99999 gives 6789 as remainder.

It is a plaindrome in base 10.

It is a self number, because there is not a number n which added to its sum of digits gives 678999999.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (678999949) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1098397 + ... + 1099014.

It is an arithmetic number, because the mean of its divisors is an integer number (114265424).

Almost surely, 2^678999999 is an apocalyptic number.

678999999 is a deficient number, since it is larger than the sum of its proper divisors (235123393).

678999999 is a wasteful number, since it uses less digits than its factorization.

678999999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2197517.

The product of its digits is 178564176, while the sum is 75.

The square root of 678999999 is about 26057.6284224025. The cubic root of 678999999 is about 878.9346607900.

The spelling of 678999999 in words is "six hundred seventy-eight million, nine hundred ninety-nine thousand, nine hundred ninety-nine".