28523509 has 8 divisors (see below), whose sum is σ = 33045440. Its totient is φ = 24113376.

The previous prime is 28523507. The next prime is 28523513. The reversal of 28523509 is 90532582.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 28523509 - 2¹ = 28523507 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28523507) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 27399 + ... + 28420.

It is an arithmetic number, because the mean of its divisors is an integer number (4130680).

Almost surely, 2^28523509 is an apocalyptic number.

It is an amenable number.

28523509 is a deficient number, since it is larger than the sum of its proper divisors (4521931).

28523509 is an equidigital number, since it uses as much as digits as its factorization.

28523509 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 55899.

The product of its (nonzero) digits is 21600, while the sum is 34.

The square root of 28523509 is about 5340.7404917296. The cubic root of 28523509 is about 305.5397019555.

The spelling of 28523509 in words is "twenty-eight million, five hundred twenty-three thousand, five hundred nine".