681705 has 12 divisors (see below), whose sum is σ = 1181700. Its totient is φ = 363552.

The previous prime is 681689. The next prime is 681719. The reversal of 681705 is 507186.

It can be written as a sum of positive squares in 2 ways, for example, as 363609 + 318096 = 603^2 + 564^2 .

It is not a de Polignac number, because 681705 - 2⁴ = 681689 is a prime.

It is a super-3 number, since 3×681705³ = 950409333862432875, which contains 333 as substring.

It is an Ulam number.

It is an unprimeable number.

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 in 11 ways as a sum of consecutive naturals, for example, 7530 + ... + 7619.

It is an arithmetic number, because the mean of its divisors is an integer number (98475).

2⁶⁸¹⁷⁰⁵ is an apocalyptic number.

It is an amenable number.

681705 is a deficient number, since it is larger than the sum of its proper divisors (499995).

681705 is a wasteful number, since it uses less digits than its factorization.

681705 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15160 (or 15157 counting only the distinct ones).

The product of its (nonzero) digits is 1680, while the sum is 27.

The square root of 681705 is about 825.6542860060. The cubic root of 681705 is about 88.0100281272.

The spelling of 681705 in words is "six hundred eighty-one thousand, seven hundred five".