681841 has 2 divisors, whose sum is σ = 681842. Its totient is φ = 681840.

The previous prime is 681839. The next prime is 681883. The reversal of 681841 is 148186.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 608400 + 73441 = 780^2 + 271^2 .

It is a cyclic number.

It is not a de Polignac number, because 681841 - 2¹ = 681839 is a prime.

Together with 681839, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (681041) 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 as a sum of consecutive naturals, namely, 340920 + 340921.

It is an arithmetic number, because the mean of its divisors is an integer number (340921).

2⁶⁸¹⁸⁴¹ is an apocalyptic number.

It is an amenable number.

681841 is a deficient number, since it is larger than the sum of its proper divisors (1).

681841 is an equidigital number, since it uses as much as digits as its factorization.

681841 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1536, while the sum is 28.

The square root of 681841 is about 825.7366408244. The cubic root of 681841 is about 88.0158803985.

It can be divided in two parts, 6818 and 41, that added together give a cube (6859 = 19³).

The spelling of 681841 in words is "six hundred eighty-one thousand, eight hundred forty-one".