681908 has 12 divisors (see below), whose sum is σ = 1200192. Its totient is φ = 339000.

The previous prime is 681899. The next prime is 681913. The reversal of 681908 is 809186.

It is a congruent number.

It is an unprimeable number.

681908 is an untouchable number, because it is not equal to the sum of proper divisors of any 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 3 ways as a sum of consecutive naturals, for example, 533 + ... + 1283.

It is an arithmetic number, because the mean of its divisors is an integer number (100016).

2⁶⁸¹⁹⁰⁸ is an apocalyptic number.

It is an amenable number.

681908 is a deficient number, since it is larger than the sum of its proper divisors (518284).

681908 is a wasteful number, since it uses less digits than its factorization.

681908 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 982 (or 980 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 32.

The square root of 681908 is about 825.7772096637. Note that the first 3 decimals coincide. The cubic root of 681908 is about 88.0187632167.

The spelling of 681908 in words is "six hundred eighty-one thousand, nine hundred eight".