281987 has 4 divisors (see below), whose sum is σ = 283080. Its totient is φ = 280896.

The previous prime is 281971. The next prime is 281989. The reversal of 281987 is 789182.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 281987 - 2⁴ = 281971 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 281987.

It is not an unprimeable number, because it can be changed into a prime (281989) 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, 83 + ... + 755.

It is an arithmetic number, because the mean of its divisors is an integer number (70770).

2²⁸¹⁹⁸⁷ is an apocalyptic number.

281987 is a deficient number, since it is larger than the sum of its proper divisors (1093).

281987 is an equidigital number, since it uses as much as digits as its factorization.

281987 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1092.

The product of its digits is 8064, while the sum is 35.

The square root of 281987 is about 531.0244815449. The cubic root of 281987 is about 65.5757141661.

The spelling of 281987 in words is "two hundred eighty-one thousand, nine hundred eighty-seven".