681767 has 4 divisors (see below), whose sum is σ = 683760. Its totient is φ = 679776.

The previous prime is 681763. The next prime is 681773. The reversal of 681767 is 767186.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 681767 - 2² = 681763 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 681767.

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

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, 338 + ... + 1215.

It is an arithmetic number, because the mean of its divisors is an integer number (170940).

2⁶⁸¹⁷⁶⁷ is an apocalyptic number.

681767 is a deficient number, since it is larger than the sum of its proper divisors (1993).

681767 is a wasteful number, since it uses less digits than its factorization.

681767 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1992.

The product of its digits is 14112, while the sum is 35.

The square root of 681767 is about 825.6918311331. The cubic root of 681767 is about 88.0126961709.

The spelling of 681767 in words is "six hundred eighty-one thousand, seven hundred sixty-seven".