28321013 has 8 divisors (see below), whose sum is σ = 32536128. Its totient is φ = 24148224.

The previous prime is 28320979. The next prime is 28321061. The reversal of 28321013 is 31012382.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 28321013 - 2¹⁸ = 28058869 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 (28321063) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9131 + ... + 11832.

It is an arithmetic number, because the mean of its divisors is an integer number (4067016).

Almost surely, 2^28321013 is an apocalyptic number.

It is an amenable number.

28321013 is a deficient number, since it is larger than the sum of its proper divisors (4215115).

28321013 is a wasteful number, since it uses less digits than its factorization.

28321013 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21163.

The product of its (nonzero) digits is 288, while the sum is 20.

The square root of 28321013 is about 5321.7490545872. The cubic root of 28321013 is about 304.8149482144.

Adding to 28321013 its reverse (31012382), we get a palindrome (59333395).

The spelling of 28321013 in words is "twenty-eight million, three hundred twenty-one thousand, thirteen".