681320 has 16 divisors (see below), whose sum is σ = 1533060. Its totient is φ = 272512.

The previous prime is 681311. The next prime is 681337. The reversal of 681320 is 23186.

It can be written as a sum of positive squares in 2 ways, for example, as 649636 + 31684 = 806^2 + 178^2 .

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a junction number, because it is equal to n+sod(n) for n = 681292 and 681301.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 681320.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8477 + ... + 8556.

2⁶⁸¹³²⁰ is an apocalyptic number.

It is an amenable number.

681320 is an abundant number, since it is smaller than the sum of its proper divisors (851740).

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

681320 is a wasteful number, since it uses less digits than its factorization.

681320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17044 (or 17040 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 20.

The square root of 681320 is about 825.4211046490. The cubic root of 681320 is about 87.9934568138.

It can be divided in two parts, 681 and 320, that added together give a palindrome (1001).

The spelling of 681320 in words is "six hundred eighty-one thousand, three hundred twenty".