681305 has 4 divisors (see below), whose sum is σ = 817572. Its totient is φ = 545040.

The previous prime is 681293. The next prime is 681311. The reversal of 681305 is 503186.

681305 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 529984 + 151321 = 728^2 + 389^2 .

It is not a de Polignac number, because 681305 - 2⁸ = 681049 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 68126 + ... + 68135.

It is an arithmetic number, because the mean of its divisors is an integer number (204393).

2⁶⁸¹³⁰⁵ is an apocalyptic number.

It is an amenable number.

681305 is a deficient number, since it is larger than the sum of its proper divisors (136267).

681305 is a wasteful number, since it uses less digits than its factorization.

681305 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 136266.

The product of its (nonzero) digits is 720, while the sum is 23.

The square root of 681305 is about 825.4120183278. The cubic root of 681305 is about 87.9928110519.

The spelling of 681305 in words is "six hundred eighty-one thousand, three hundred five".