681858 has 48 divisors (see below), whose sum is σ = 1624896. Its totient is φ = 213840.

The previous prime is 681841. The next prime is 681883. The reversal of 681858 is 858186.

It is a Curzon number.

It is an unprimeable number.

681858 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 23 ways as a sum of consecutive naturals, for example, 11148 + ... + 11208.

It is an arithmetic number, because the mean of its divisors is an integer number (33852).

2⁶⁸¹⁸⁵⁸ is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 681858, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (812448).

681858 is an abundant number, since it is smaller than the sum of its proper divisors (943038).

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

681858 is a wasteful number, since it uses less digits than its factorization.

681858 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 101 (or 89 counting only the distinct ones).

The product of its digits is 15360, while the sum is 36.

The square root of 681858 is about 825.7469345992. The cubic root of 681858 is about 88.0166118777.

The spelling of 681858 in words is "six hundred eighty-one thousand, eight hundred fifty-eight".