281389 has 4 divisors (see below), whose sum is σ = 287424. Its totient is φ = 275356.

The previous prime is 281381. The next prime is 281419. The reversal of 281389 is 983182.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 983182 = 2 ⋅491591.

It is a cyclic number.

It is not a de Polignac number, because 281389 - 2³ = 281381 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 281389.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (281381) 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, 2947 + ... + 3040.

It is an arithmetic number, because the mean of its divisors is an integer number (71856).

2²⁸¹³⁸⁹ is an apocalyptic number.

It is an amenable number.

281389 is a deficient number, since it is larger than the sum of its proper divisors (6035).

281389 is an equidigital number, since it uses as much as digits as its factorization.

281389 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6034.

The product of its digits is 3456, while the sum is 31.

The square root of 281389 is about 530.4611201587. The cubic root of 281389 is about 65.5293266495.

The spelling of 281389 in words is "two hundred eighty-one thousand, three hundred eighty-nine".