681706 has 8 divisors (see below), whose sum is σ = 1027044. Its totient is φ = 339360.

The previous prime is 681689. The next prime is 681719. The reversal of 681706 is 607186.

It can be written as a sum of positive squares in 2 ways, for example, as 654481 + 27225 = 809^2 + 165^2 .

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 45 + ... + 1168.

2⁶⁸¹⁷⁰⁶ is an apocalyptic number.

681706 is a deficient number, since it is larger than the sum of its proper divisors (345338).

681706 is a wasteful number, since it uses less digits than its factorization.

681706 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1496.

The product of its (nonzero) digits is 2016, while the sum is 28.

The square root of 681706 is about 825.6548915861. The cubic root of 681706 is about 88.0100711614.

The spelling of 681706 in words is "six hundred eighty-one thousand, seven hundred six".