28000321 has 2 divisors, whose sum is σ = 28000322. Its totient is φ = 28000320.

The previous prime is 28000237. The next prime is 28000337. The reversal of 28000321 is 12300082.

It is a happy number.

It is an a-pointer prime, because the next prime (28000337) can be obtained adding 28000321 to its sum of digits (16).

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 25644096 + 2356225 = 5064^2 + 1535^2 .

It is a cyclic number.

It is not a de Polignac number, because 28000321 - 2²¹ = 25903169 is a prime.

It is a super-2 number, since 2×28000321² = 1568035952206082, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 28000295 and 28000304.

It is not a weakly prime, because it can be changed into another prime (28000381) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14000160 + 14000161.

It is an arithmetic number, because the mean of its divisors is an integer number (14000161).

Almost surely, 2^28000321 is an apocalyptic number.

It is an amenable number.

28000321 is a deficient number, since it is larger than the sum of its proper divisors (1).

28000321 is an equidigital number, since it uses as much as digits as its factorization.

28000321 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 96, while the sum is 16.

The square root of 28000321 is about 5291.5329536912. The cubic root of 28000321 is about 303.6600575939.

The spelling of 28000321 in words is "twenty-eight million, three hundred twenty-one", and thus it is an aban number.