681804 has 48 divisors (see below), whose sum is σ = 1814400. Its totient is φ = 221328.

The previous prime is 681787. The next prime is 681809. The reversal of 681804 is 408186.

681804 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a hoax number, since the sum of its digits (27) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (681809) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6319 + ... + 6425.

It is an arithmetic number, because the mean of its divisors is an integer number (37800).

2⁶⁸¹⁸⁰⁴ 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 681804, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (907200).

681804 is an abundant number, since it is smaller than the sum of its proper divisors (1132596).

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

681804 is a wasteful number, since it uses less digits than its factorization.

681804 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 179 (or 171 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 27.

The square root of 681804 is about 825.7142362827. The cubic root of 681804 is about 88.0142883135.

681804 divided by its sum of digits (27) gives a palindrome (25252).

It can be divided in two parts, 681 and 804, that added together give a triangular number (1485 = T₅₄).

The spelling of 681804 in words is "six hundred eighty-one thousand, eight hundred four".