281863 has 4 divisors (see below), whose sum is σ = 285120. Its totient is φ = 278608.

The previous prime is 281857. The next prime is 281867. The reversal of 281863 is 368182.

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

It is a cyclic number.

It is not a de Polignac number, because 281863 - 2¹⁷ = 150791 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (281867) 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, 1495 + ... + 1672.

It is an arithmetic number, because the mean of its divisors is an integer number (71280).

2²⁸¹⁸⁶³ is an apocalyptic number.

281863 is a deficient number, since it is larger than the sum of its proper divisors (3257).

281863 is an equidigital number, since it uses as much as digits as its factorization.

281863 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3256.

The product of its digits is 2304, while the sum is 28.

The square root of 281863 is about 530.9077132610. The cubic root of 281863 is about 65.5661007433.

It can be divided in two parts, 28 and 1863, that added together give a triangular number (1891 = T₆₁).

The spelling of 281863 in words is "two hundred eighty-one thousand, eight hundred sixty-three".