678646864 has 120 divisors (see below), whose sum is σ = 1666634400. Its totient is φ = 265870080.

The previous prime is 678646781. The next prime is 678646879. The reversal of 678646864 is 468646876.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 431199 + ... + 432769.

It is an arithmetic number, because the mean of its divisors is an integer number (13888620).

Almost surely, 2^678646864 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 678646864, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (833317200).

678646864 is an abundant number, since it is smaller than the sum of its proper divisors (987987536).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

678646864 is a wasteful number, since it uses less digits than its factorization.

678646864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1641 (or 1628 counting only the distinct ones).

The product of its digits is 9289728, while the sum is 55.

The square root of 678646864 is about 26050.8515023982. The cubic root of 678646864 is about 878.7822619606.

The spelling of 678646864 in words is "six hundred seventy-eight million, six hundred forty-six thousand, eight hundred sixty-four".