28321331 has 2 divisors, whose sum is σ = 28321332. Its totient is φ = 28321330.

The previous prime is 28321301. The next prime is 28321339. The reversal of 28321331 is 13312382.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 28321331 - 2¹⁰ = 28320307 is a prime.

It is a super-2 number, since 2×28321331² = 1604195579223122, which contains 22 as substring.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 28321297 and 28321306.

It is not a weakly prime, because it can be changed into another prime (28321339) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14160665 + 14160666.

It is an arithmetic number, because the mean of its divisors is an integer number (14160666).

Almost surely, 2^28321331 is an apocalyptic number.

28321331 is a deficient number, since it is larger than the sum of its proper divisors (1).

28321331 is an equidigital number, since it uses as much as digits as its factorization.

28321331 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 864, while the sum is 23.

The square root of 28321331 is about 5321.7789318986. The cubic root of 28321331 is about 304.8160890727.

The spelling of 28321331 in words is "twenty-eight million, three hundred twenty-one thousand, three hundred thirty-one".