681968 has 20 divisors (see below), whose sum is σ = 1510320. Its totient is φ = 292224.

The previous prime is 681949. The next prime is 681971. The reversal of 681968 is 869186.

It is a Smith number, since the sum of its digits (38) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is an unprimeable number.

681968 is an untouchable number, because it is not equal to the sum of proper divisors of any 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, 2933 + ... + 3156.

It is an arithmetic number, because the mean of its divisors is an integer number (75516).

2⁶⁸¹⁹⁶⁸ is an apocalyptic number.

It is an amenable number.

681968 is an abundant number, since it is smaller than the sum of its proper divisors (828352).

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

681968 is a wasteful number, since it uses less digits than its factorization.

681968 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6104 (or 6098 counting only the distinct ones).

The product of its digits is 20736, while the sum is 38.

The square root of 681968 is about 825.8135382760. The cubic root of 681968 is about 88.0213446846.

The spelling of 681968 in words is "six hundred eighty-one thousand, nine hundred sixty-eight".