28725519 has 4 divisors (see below), whose sum is σ = 38300696. Its totient is φ = 19150344.

The previous prime is 28725517. The next prime is 28725527. The reversal of 28725519 is 91552782.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 28725519 - 2¹ = 28725517 is a prime.

It is a super-2 number, since 2×28725519² = 1650310883638722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28725517) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4787584 + ... + 4787589.

It is an arithmetic number, because the mean of its divisors is an integer number (9575174).

Almost surely, 2^28725519 is an apocalyptic number.

28725519 is a deficient number, since it is larger than the sum of its proper divisors (9575177).

28725519 is an equidigital number, since it uses as much as digits as its factorization.

28725519 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9575176.

The product of its digits is 50400, while the sum is 39.

The square root of 28725519 is about 5359.6192961814. The cubic root of 28725519 is about 306.2593064505.

The spelling of 28725519 in words is "twenty-eight million, seven hundred twenty-five thousand, five hundred nineteen".