681603 has 8 divisors (see below), whose sum is σ = 978768. Its totient is φ = 419424.

The previous prime is 681589. The next prime is 681607. The reversal of 681603 is 306186.

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

It is not a de Polignac number, because 681603 - 2⁶ = 681539 is a prime.

681603 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, 8700 + ... + 8777.

It is an arithmetic number, because the mean of its divisors is an integer number (122346).

2⁶⁸¹⁶⁰³ is an apocalyptic number.

681603 is a deficient number, since it is larger than the sum of its proper divisors (297165).

681603 is a wasteful number, since it uses less digits than its factorization.

681603 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17493.

The product of its (nonzero) digits is 864, while the sum is 24.

The square root of 681603 is about 825.5925145009. The cubic root of 681603 is about 88.0056384128.

Adding to 681603 its reverse (306186), we get a palindrome (987789).

It can be divided in two parts, 68160 and 3, that multiplied together give a triangular number (204480 = T₆₃₉).

The spelling of 681603 in words is "six hundred eighty-one thousand, six hundred three".