681743 has 4 divisors (see below), whose sum is σ = 711408. Its totient is φ = 652080.

The previous prime is 681731. The next prime is 681763. The reversal of 681743 is 347186.

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 681743 - 2⁴ = 681727 is a prime.

It is a Duffinian number.

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 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, 14798 + ... + 14843.

It is an arithmetic number, because the mean of its divisors is an integer number (177852).

2⁶⁸¹⁷⁴³ is an apocalyptic number.

681743 is a deficient number, since it is larger than the sum of its proper divisors (29665).

681743 is a wasteful number, since it uses less digits than its factorization.

681743 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29664.

The product of its digits is 4032, while the sum is 29.

The square root of 681743 is about 825.6772977380. The cubic root of 681743 is about 88.0116633990.

The spelling of 681743 in words is "six hundred eighty-one thousand, seven hundred forty-three".