681704 has 8 divisors (see below), whose sum is σ = 1278210. Its totient is φ = 340848.

The previous prime is 681689. The next prime is 681719. The reversal of 681704 is 407186.

681704 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (681689) and next prime (681719).

It can be written as a sum of positive squares in only one way, i.e., 592900 + 88804 = 770^2 + 298^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is an unprimeable number.

681704 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 42599 + ... + 42614.

2⁶⁸¹⁷⁰⁴ is an apocalyptic number.

It is an amenable number.

681704 is a deficient number, since it is larger than the sum of its proper divisors (596506).

681704 is a wasteful number, since it uses less digits than its factorization.

681704 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 85219 (or 85215 counting only the distinct ones).

The product of its (nonzero) digits is 1344, while the sum is 26.

The square root of 681704 is about 825.6536804254. The cubic root of 681704 is about 88.0099850929.

The spelling of 681704 in words is "six hundred eighty-one thousand, seven hundred four".