28294321 has 4 divisors (see below), whose sum is σ = 30866544. Its totient is φ = 25722100.

The previous prime is 28294319. The next prime is 28294327. The reversal of 28294321 is 12349282.

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 28294321 - 2¹ = 28294319 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28294327) 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, 1286095 + ... + 1286116.

It is an arithmetic number, because the mean of its divisors is an integer number (7716636).

Almost surely, 2^28294321 is an apocalyptic number.

It is an amenable number.

28294321 is a deficient number, since it is larger than the sum of its proper divisors (2572223).

28294321 is a wasteful number, since it uses less digits than its factorization.

28294321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2572222.

The product of its digits is 6912, while the sum is 31.

The square root of 28294321 is about 5319.2406412946. The cubic root of 28294321 is about 304.7191574084.

The spelling of 28294321 in words is "twenty-eight million, two hundred ninety-four thousand, three hundred twenty-one".