681366 has 16 divisors (see below), whose sum is σ = 1557504. Its totient is φ = 194664.

The previous prime is 681361. The next prime is 681367. The reversal of 681366 is 663186.

681366 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (681361) by changing a digit.

681366 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 7 ways as a sum of consecutive naturals, for example, 8070 + ... + 8153.

It is an arithmetic number, because the mean of its divisors is an integer number (97344).

2⁶⁸¹³⁶⁶ is an apocalyptic number.

681366 is an abundant number, since it is smaller than the sum of its proper divisors (876138).

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

681366 is a wasteful number, since it uses less digits than its factorization.

681366 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16235.

The product of its digits is 5184, while the sum is 30.

The square root of 681366 is about 825.4489687437. The cubic root of 681366 is about 87.9954370912.

The spelling of 681366 in words is "six hundred eighty-one thousand, three hundred sixty-six".