28247 has 4 divisors (see below), whose sum is σ = 28896. Its totient is φ = 27600.

The previous prime is 28229. The next prime is 28277. The reversal of 28247 is 74282.

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 28247 - 2⁶ = 28183 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 28247.

It is not an unprimeable number, because it can be changed into a prime (28277) 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, 254 + ... + 347.

It is an arithmetic number, because the mean of its divisors is an integer number (7224).

2²⁸²⁴⁷ is an apocalyptic number.

28247 is a deficient number, since it is larger than the sum of its proper divisors (649).

28247 is an equidigital number, since it uses as much as digits as its factorization.

28247 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 648.

The product of its digits is 896, while the sum is 23.

The square root of 28247 is about 168.0684384410. The cubic root of 28247 is about 30.4549186181.

Subtracting from 28247 its sum of digits (23), we obtain a square (28224 = 168²).

The spelling of 28247 in words is "twenty-eight thousand, two hundred forty-seven".