681861 has 8 divisors (see below), whose sum is σ = 915264. Its totient is φ = 451520.

The previous prime is 681841. The next prime is 681883. The reversal of 681861 is 168186.

681861 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 681861 - 2¹³ = 673669 is a prime.

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 polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 180 + ... + 1181.

It is an arithmetic number, because the mean of its divisors is an integer number (114408).

2⁶⁸¹⁸⁶¹ is an apocalyptic number.

It is an amenable number.

681861 is a deficient number, since it is larger than the sum of its proper divisors (233403).

681861 is a wasteful number, since it uses less digits than its factorization.

681861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1531.

The product of its digits is 2304, while the sum is 30.

The square root of 681861 is about 825.7487511344. The cubic root of 681861 is about 88.0167409610.

The spelling of 681861 in words is "six hundred eighty-one thousand, eight hundred sixty-one".