681328 has 20 divisors (see below), whose sum is σ = 1336720. Its totient is φ = 336384.

The previous prime is 681311. The next prime is 681337. The reversal of 681328 is 823186.

It is a junction number, because it is equal to n+sod(n) for n = 681296 and 681305.

It is a congruent number.

It is an unprimeable number.

681328 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 in 3 ways as a sum of consecutive naturals, for example, 1333 + ... + 1771.

It is an arithmetic number, because the mean of its divisors is an integer number (66836).

2⁶⁸¹³²⁸ is an apocalyptic number.

It is an amenable number.

681328 is a deficient number, since it is larger than the sum of its proper divisors (655392).

681328 is a wasteful number, since it uses less digits than its factorization.

681328 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 544 (or 538 counting only the distinct ones).

The product of its digits is 2304, while the sum is 28.

The square root of 681328 is about 825.4259506461. The cubic root of 681328 is about 87.9938012163.

The spelling of 681328 in words is "six hundred eighty-one thousand, three hundred twenty-eight".