28520447 has 2 divisors, whose sum is σ = 28520448. Its totient is φ = 28520446.

The previous prime is 28520419. The next prime is 28520449. The reversal of 28520447 is 74402582.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 28520447 - 2⁶ = 28520383 is a prime.

Together with 28520449, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28520449) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14260223 + 14260224.

It is an arithmetic number, because the mean of its divisors is an integer number (14260224).

Almost surely, 2^28520447 is an apocalyptic number.

28520447 is a deficient number, since it is larger than the sum of its proper divisors (1).

28520447 is an equidigital number, since it uses as much as digits as its factorization.

28520447 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 17920, while the sum is 32.

The square root of 28520447 is about 5340.4538196674. The cubic root of 28520447 is about 305.5287683306.

The spelling of 28520447 in words is "twenty-eight million, five hundred twenty thousand, four hundred forty-seven".