681851 has 8 divisors (see below), whose sum is σ = 709104. Its totient is φ = 655200.

The previous prime is 681841. The next prime is 681883. The reversal of 681851 is 158186.

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

It is a cyclic number.

It is not a de Polignac number, because 681851 - 2⁶ = 681787 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (681841) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4265 + ... + 4421.

It is an arithmetic number, because the mean of its divisors is an integer number (88638).

2⁶⁸¹⁸⁵¹ is an apocalyptic number.

681851 is a deficient number, since it is larger than the sum of its proper divisors (27253).

681851 is a wasteful number, since it uses less digits than its factorization.

681851 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 301.

The product of its digits is 1920, while the sum is 29.

The square root of 681851 is about 825.7426960016. The cubic root of 681851 is about 88.0163106819.

It can be divided in two parts, 68185 and 1, that added together give a palindrome (68186).

The spelling of 681851 in words is "six hundred eighty-one thousand, eight hundred fifty-one".