681091 has 2 divisors, whose sum is σ = 681092. Its totient is φ = 681090.

The previous prime is 681089. The next prime is 681113. The reversal of 681091 is 190186.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 681091 - 2¹ = 681089 is a prime.

Together with 681089, it forms a pair of twin primes.

It is a zygodrome in base 6.

It is not a weakly prime, because it can be changed into another prime (681001) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 340545 + 340546.

It is an arithmetic number, because the mean of its divisors is an integer number (340546).

2⁶⁸¹⁰⁹¹ is an apocalyptic number.

681091 is a deficient number, since it is larger than the sum of its proper divisors (1).

681091 is an equidigital number, since it uses as much as digits as its factorization.

681091 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 432, while the sum is 25.

The square root of 681091 is about 825.2823759175. The cubic root of 681091 is about 87.9835971494.

The spelling of 681091 in words is "six hundred eighty-one thousand, ninety-one".