681281 has 4 divisors (see below), whose sum is σ = 699732. Its totient is φ = 662832.

The previous prime is 681271. The next prime is 681293. The reversal of 681281 is 182186.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 410881 + 270400 = 641^2 + 520^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-681281 is a prime.

It is a super-2 number, since 2×681281² = 928287601922, which contains 22 as substring.

It is a Duffinian number.

It is a nialpdrome in base 16.

It is a self number, because there is not a number n which added to its sum of digits gives 681281.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 681281.

It is not an unprimeable number, because it can be changed into a prime (681221) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9170 + ... + 9243.

It is an arithmetic number, because the mean of its divisors is an integer number (174933).

2⁶⁸¹²⁸¹ is an apocalyptic number.

It is an amenable number.

681281 is a deficient number, since it is larger than the sum of its proper divisors (18451).

681281 is a wasteful number, since it uses less digits than its factorization.

681281 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18450.

The product of its digits is 768, while the sum is 26.

The square root of 681281 is about 825.3974800058. The cubic root of 681281 is about 87.9917778131.

The spelling of 681281 in words is "six hundred eighty-one thousand, two hundred eighty-one".