681924 has 12 divisors (see below), whose sum is σ = 1591184. Its totient is φ = 227304.

The previous prime is 681913. The next prime is 681931. The reversal of 681924 is 429186.

681924 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (12).

It is a junction number, because it is equal to n+sod(n) for n = 681891 and 681900.

It is an unprimeable number.

681924 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is an upside-down number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 28402 + ... + 28425.

2⁶⁸¹⁹²⁴ is an apocalyptic number.

It is an amenable number.

681924 is an abundant number, since it is smaller than the sum of its proper divisors (909260).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

681924 is a wasteful number, since it uses less digits than its factorization.

681924 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 56834 (or 56832 counting only the distinct ones).

The product of its digits is 3456, while the sum is 30.

The square root of 681924 is about 825.7868974499. The cubic root of 681924 is about 88.0194516229.

The spelling of 681924 in words is "six hundred eighty-one thousand, nine hundred twenty-four".