281688 has 48 divisors (see below), whose sum is σ = 782040. Its totient is φ = 84480.

The previous prime is 281683. The next prime is 281717. The reversal of 281688 is 886182.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a nude number because it is divisible by every one of its digits.

Its product of digits (6144) is a multiple of the sum of its prime factors (128).

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 281688.

It is not an unprimeable number, because it can be changed into a prime (281683) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2856 + ... + 2952.

2²⁸¹⁶⁸⁸ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 281688, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (391020).

281688 is an abundant number, since it is smaller than the sum of its proper divisors (500352).

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

281688 is a wasteful number, since it uses less digits than its factorization.

281688 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 128 (or 113 counting only the distinct ones).

The product of its digits is 6144, while the sum is 33.

The square root of 281688 is about 530.7428755999. The cubic root of 281688 is about 65.5525286142.

It can be divided in two parts, 281 and 688, that added together give a palindrome (969).

The spelling of 281688 in words is "two hundred eighty-one thousand, six hundred eighty-eight".