28228665 has 16 divisors (see below), whose sum is σ = 45907776. Its totient is φ = 14808000.

The previous prime is 28228663. The next prime is 28228691. The reversal of 28228665 is 56682282.

It is not a de Polignac number, because 28228665 - 2¹ = 28228663 is a prime.

It is not an unprimeable number, because it can be changed into a prime (28228663) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 14511 + ... + 16340.

It is an arithmetic number, because the mean of its divisors is an integer number (2869236).

Almost surely, 2^28228665 is an apocalyptic number.

It is an amenable number.

28228665 is a deficient number, since it is larger than the sum of its proper divisors (17679111).

28228665 is a wasteful number, since it uses less digits than its factorization.

28228665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30920.

The product of its digits is 92160, while the sum is 39.

The square root of 28228665 is about 5313.0654993139. The cubic root of 28228665 is about 304.4832780850.

The spelling of 28228665 in words is "twenty-eight million, two hundred twenty-eight thousand, six hundred sixty-five".