284721 has 4 divisors (see below), whose sum is σ = 379632. Its totient is φ = 189812.

The previous prime is 284707. The next prime is 284723. The reversal of 284721 is 127482.

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.

It is a cyclic number.

It is not a de Polignac number, because 284721 - 2⁵ = 284689 is a prime.

It is a D-number.

It is a junction number, because it is equal to n+sod(n) for n = 284691 and 284700.

It is not an unprimeable number, because it can be changed into a prime (284723) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 47451 + ... + 47456.

It is an arithmetic number, because the mean of its divisors is an integer number (94908).

2²⁸⁴⁷²¹ is an apocalyptic number.

It is an amenable number.

284721 is a deficient number, since it is larger than the sum of its proper divisors (94911).

284721 is an equidigital number, since it uses as much as digits as its factorization.

284721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 94910.

The product of its digits is 896, while the sum is 24.

The square root of 284721 is about 533.5925411773. The cubic root of 284721 is about 65.7869623069.

The spelling of 284721 in words is "two hundred eighty-four thousand, seven hundred twenty-one".