681847 has 4 divisors (see below), whose sum is σ = 684376. Its totient is φ = 679320.

The previous prime is 681841. The next prime is 681883. The reversal of 681847 is 748186.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 748186 = 2 ⋅374093.

It is a cyclic number.

It is not a de Polignac number, because 681847 - 2³ = 681839 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 (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 3 ways as a sum of consecutive naturals, for example, 804 + ... + 1417.

It is an arithmetic number, because the mean of its divisors is an integer number (171094).

2⁶⁸¹⁸⁴⁷ is an apocalyptic number.

681847 is a deficient number, since it is larger than the sum of its proper divisors (2529).

681847 is a wasteful number, since it uses less digits than its factorization.

681847 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2528.

The product of its digits is 10752, while the sum is 34.

The square root of 681847 is about 825.7402739361. The cubic root of 681847 is about 88.0161385690.

The spelling of 681847 in words is "six hundred eighty-one thousand, eight hundred forty-seven".