681608 has 8 divisors (see below), whose sum is σ = 1278030. Its totient is φ = 340800.

The previous prime is 681607. The next prime is 681613. The reversal of 681608 is 806186.

It can be written as a sum of positive squares in only one way, i.e., 550564 + 131044 = 742^2 + 362^2 .

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

It is not an unprimeable number, because it can be changed into a prime (681607) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 42593 + ... + 42608.

2⁶⁸¹⁶⁰⁸ is an apocalyptic number.

It is an amenable number.

681608 is a deficient number, since it is larger than the sum of its proper divisors (596422).

681608 is a wasteful number, since it uses less digits than its factorization.

681608 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 85207 (or 85203 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 29.

The square root of 681608 is about 825.5955426236. The cubic root of 681608 is about 88.0058536051.

The spelling of 681608 in words is "six hundred eighty-one thousand, six hundred eight".