28228615 has 4 divisors (see below), whose sum is σ = 33874344. Its totient is φ = 22582888.

The previous prime is 28228573. The next prime is 28228621. The reversal of 28228615 is 51682282.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28228615 is a prime.

It is a Duffinian number.

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, 2822857 + ... + 2822866.

It is an arithmetic number, because the mean of its divisors is an integer number (8468586).

Almost surely, 2^28228615 is an apocalyptic number.

28228615 is a deficient number, since it is larger than the sum of its proper divisors (5645729).

28228615 is an equidigital number, since it uses as much as digits as its factorization.

28228615 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5645728.

The product of its digits is 15360, while the sum is 34.

The square root of 28228615 is about 5313.0607939304. The cubic root of 28228615 is about 304.4830983129.

The spelling of 28228615 in words is "twenty-eight million, two hundred twenty-eight thousand, six hundred fifteen".