681738 has 8 divisors (see below), whose sum is σ = 1363488. Its totient is φ = 227244.

The previous prime is 681731. The next prime is 681763. The reversal of 681738 is 837186.

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

681738 is an admirable number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 681699 and 681708.

It is not an unprimeable number, because it can be changed into a prime (681731) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 56806 + ... + 56817.

It is an arithmetic number, because the mean of its divisors is an integer number (170436).

2⁶⁸¹⁷³⁸ is an apocalyptic number.

681738 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

681738 is a wasteful number, since it uses less digits than its factorization.

681738 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 113628.

The product of its digits is 8064, while the sum is 33.

The square root of 681738 is about 825.6742699152. The cubic root of 681738 is about 88.0114482351.

The spelling of 681738 in words is "six hundred eighty-one thousand, seven hundred thirty-eight".