681831 has 8 divisors (see below), whose sum is σ = 1010160. Its totient is φ = 454536.

The previous prime is 681823. The next prime is 681833. The reversal of 681831 is 138186.

It is not a de Polignac number, because 681831 - 2³ = 681823 is a prime.

It is a super-2 number, since 2×681831² = 929787025122, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27), and also a Moran number because the ratio is a prime number: 25253 = 681831 / (6 + 8 + 1 + 8 + 3 + 1).

681831 is a lucky number.

It is a junction number, because it is equal to n+sod(n) for n = 681795 and 681804.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (681833) 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, 12600 + ... + 12653.

It is an arithmetic number, because the mean of its divisors is an integer number (126270).

2⁶⁸¹⁸³¹ is an apocalyptic number.

681831 is a deficient number, since it is larger than the sum of its proper divisors (328329).

681831 is a wasteful number, since it uses less digits than its factorization.

681831 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25262 (or 25256 counting only the distinct ones).

The product of its digits is 1152, while the sum is 27.

The square root of 681831 is about 825.7305856028. The cubic root of 681831 is about 88.0154501110.

The spelling of 681831 in words is "six hundred eighty-one thousand, eight hundred thirty-one".