28442321 has 2 divisors, whose sum is σ = 28442322. Its totient is φ = 28442320.

The previous prime is 28442311. The next prime is 28442347. The reversal of 28442321 is 12324482.

It is an a-pointer prime, because the next prime (28442347) can be obtained adding 28442321 to its sum of digits (26).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16443025 + 11999296 = 4055^2 + 3464^2 .

It is a cyclic number.

It is not a de Polignac number, because 28442321 - 2¹⁸ = 28180177 is a prime.

It is not a weakly prime, because it can be changed into another prime (28442311) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14221160 + 14221161.

It is an arithmetic number, because the mean of its divisors is an integer number (14221161).

Almost surely, 2^28442321 is an apocalyptic number.

It is an amenable number.

28442321 is a deficient number, since it is larger than the sum of its proper divisors (1).

28442321 is an equidigital number, since it uses as much as digits as its factorization.

28442321 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3072, while the sum is 26.

The square root of 28442321 is about 5333.1342567012. The cubic root of 28442321 is about 305.2495351051.

The spelling of 28442321 in words is "twenty-eight million, four hundred forty-two thousand, three hundred twenty-one".