28388449 has 2 divisors, whose sum is σ = 28388450. Its totient is φ = 28388448.

The previous prime is 28388447. The next prime is 28388473. The reversal of 28388449 is 94488382.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 26780625 + 1607824 = 5175^2 + 1268^2 .

It is a cyclic number.

It is not a de Polignac number, because 28388449 - 2¹ = 28388447 is a prime.

It is a super-4 number, since 4×28388449⁴ (a number of 31 digits) contains 4444 as substring.

Together with 28388447, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 28388399 and 28388408.

It is not a weakly prime, because it can be changed into another prime (28388447) 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, 14194224 + 14194225.

It is an arithmetic number, because the mean of its divisors is an integer number (14194225).

Almost surely, 2^28388449 is an apocalyptic number.

It is an amenable number.

28388449 is a deficient number, since it is larger than the sum of its proper divisors (1).

28388449 is an equidigital number, since it uses as much as digits as its factorization.

28388449 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 442368, while the sum is 46.

The square root of 28388449 is about 5328.0811743066. The cubic root of 28388449 is about 305.0566910656.

The spelling of 28388449 in words is "twenty-eight million, three hundred eighty-eight thousand, four hundred forty-nine".