681697 has 8 divisors (see below), whose sum is σ = 720576. Its totient is φ = 643632.

The previous prime is 681689. The next prime is 681719. The reversal of 681697 is 796186.

681697 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is not a de Polignac number, because 681697 - 2³ = 681689 is a prime.

It is a Duffinian number.

681697 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (681607) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2323 + ... + 2599.

It is an arithmetic number, because the mean of its divisors is an integer number (90072).

2⁶⁸¹⁶⁹⁷ is an apocalyptic number.

It is an amenable number.

681697 is a deficient number, since it is larger than the sum of its proper divisors (38879).

681697 is a wasteful number, since it uses less digits than its factorization.

681697 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 407.

The product of its digits is 18144, while the sum is 37.

The square root of 681697 is about 825.6494413491. The cubic root of 681697 is about 88.0096838517.

It can be divided in two parts, 681 and 697, that added together give a triangular number (1378 = T₅₂).

The spelling of 681697 in words is "six hundred eighty-one thousand, six hundred ninety-seven".