681768 has 48 divisors (see below), whose sum is σ = 1958580. Its totient is φ = 213504.

The previous prime is 681763. The next prime is 681773. The reversal of 681768 is 867186.

It is an interprime number because it is at equal distance from previous prime (681763) and next prime (681773).

It can be written as a sum of positive squares in 2 ways, for example, as 675684 + 6084 = 822^2 + 78^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (681763) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 946 + ... + 1502.

2⁶⁸¹⁷⁶⁸ is an apocalyptic number.

681768 is a gapful number since it is divisible by the number (68) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 681768, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (979290).

681768 is an abundant number, since it is smaller than the sum of its proper divisors (1276812).

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

681768 is a wasteful number, since it uses less digits than its factorization.

681768 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 586 (or 579 counting only the distinct ones).

The product of its digits is 16128, while the sum is 36.

The square root of 681768 is about 825.6924366857. The cubic root of 681768 is about 88.0127392026.

The spelling of 681768 in words is "six hundred eighty-one thousand, seven hundred sixty-eight".