281000 has 32 divisors (see below), whose sum is σ = 659880. Its totient is φ = 112000.

The previous prime is 280997. The next prime is 281023. The reversal of 281000 is 182.

It can be written as a sum of positive squares in 4 ways, for example, as 106276 + 174724 = 326^2 + 418^2 .

It is a super-2 number, since 2×281000² = 157922000000, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 860 + ... + 1140.

2²⁸¹⁰⁰⁰ is an apocalyptic number.

281000 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 281000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (329940).

281000 is an abundant number, since it is smaller than the sum of its proper divisors (378880).

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

281000 is a wasteful number, since it uses less digits than its factorization.

281000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 302 (or 288 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 11.

The square root of 281000 is about 530.0943312279. The cubic root of 281000 is about 65.4991162012.

Adding to 281000 its reverse (182), we get a palindrome (281182).

The spelling of 281000 in words is "two hundred eighty-one thousand".