678400 has 60 divisors (see below), whose sum is σ = 1712502. Its totient is φ = 266240.

The previous prime is 678383. The next prime is 678401. The reversal of 678400 is 4876.

It can be written as a sum of positive squares in 3 ways, for example, as 565504 + 112896 = 752^2 + 336^2 .

It is a Harshad number since it is a multiple of its sum of digits (25).

It is a zygodrome in base 4.

It is not an unprimeable number, because it can be changed into a prime (678401) by changing a digit.

678400 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 12774 + ... + 12826.

2⁶⁷⁸⁴⁰⁰ 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 678400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (856251).

678400 is an abundant number, since it is smaller than the sum of its proper divisors (1034102).

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

678400 is an equidigital number, since it uses as much as digits as its factorization.

678400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 81 (or 60 counting only the distinct ones).

The product of its (nonzero) digits is 1344, while the sum is 25.

The square root of 678400 is about 823.6504112790. The cubic root of 678400 is about 87.8675694011.

The spelling of 678400 in words is "six hundred seventy-eight thousand, four hundred".