281689 has 4 divisors (see below), whose sum is σ = 284580. Its totient is φ = 278800.

The previous prime is 281683. The next prime is 281717. The reversal of 281689 is 986182.

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 233289 + 48400 = 483^2 + 220^2 .

It is a cyclic number.

It is not a de Polignac number, because 281689 - 2¹¹ = 279641 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 (281683) 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, 1294 + ... + 1495.

It is an arithmetic number, because the mean of its divisors is an integer number (71145).

2²⁸¹⁶⁸⁹ is an apocalyptic number.

It is an amenable number.

281689 is a deficient number, since it is larger than the sum of its proper divisors (2891).

281689 is a wasteful number, since it uses less digits than its factorization.

281689 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2890.

The product of its digits is 6912, while the sum is 34.

The square root of 281689 is about 530.7438176748. The cubic root of 281689 is about 65.5526061852.

The spelling of 281689 in words is "two hundred eighty-one thousand, six hundred eighty-nine".