281881 has 4 divisors (see below), whose sum is σ = 286564. Its totient is φ = 277200.

The previous prime is 281867. The next prime is 281887. The reversal of 281881 is 188182.

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 46656 + 235225 = 216^2 + 485^2 .

It is a cyclic number.

It is not a de Polignac number, because 281881 - 2⁵ = 281849 is a prime.

It is a super-2 number, since 2×281881² = 158913796322, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (281887) 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, 2250 + ... + 2371.

It is an arithmetic number, because the mean of its divisors is an integer number (71641).

2²⁸¹⁸⁸¹ is an apocalyptic number.

It is an amenable number.

281881 is a deficient number, since it is larger than the sum of its proper divisors (4683).

281881 is an equidigital number, since it uses as much as digits as its factorization.

281881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4682.

The product of its digits is 1024, while the sum is 28.

The square root of 281881 is about 530.9246650891. The cubic root of 281881 is about 65.5674964151.

The spelling of 281881 in words is "two hundred eighty-one thousand, eight hundred eighty-one".