28320415 has 4 divisors (see below), whose sum is σ = 33984504. Its totient is φ = 22656328.

The previous prime is 28320407. The next prime is 28320421. The reversal of 28320415 is 51402382.

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

It is a cyclic number.

It is not a de Polignac number, because 28320415 - 2³ = 28320407 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 28320415.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2832037 + ... + 2832046.

It is an arithmetic number, because the mean of its divisors is an integer number (8496126).

Almost surely, 2^28320415 is an apocalyptic number.

28320415 is a deficient number, since it is larger than the sum of its proper divisors (5664089).

28320415 is an equidigital number, since it uses as much as digits as its factorization.

28320415 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5664088.

The product of its (nonzero) digits is 1920, while the sum is 25.

The square root of 28320415 is about 5321.6928697549. The cubic root of 28320415 is about 304.8128028036.

Adding to 28320415 its reverse (51402382), we get a palindrome (79722797).

The spelling of 28320415 in words is "twenty-eight million, three hundred twenty thousand, four hundred fifteen".