28228971 has 4 divisors (see below), whose sum is σ = 37638632. Its totient is φ = 18819312.

The previous prime is 28228969. The next prime is 28228973. The reversal of 28228971 is 17982282.

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

It is an interprime number because it is at equal distance from previous prime (28228969) and next prime (28228973).

It is not a de Polignac number, because 28228971 - 2¹ = 28228969 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28228973) 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 3 ways as a sum of consecutive naturals, for example, 4704826 + ... + 4704831.

It is an arithmetic number, because the mean of its divisors is an integer number (9409658).

Almost surely, 2^28228971 is an apocalyptic number.

28228971 is a deficient number, since it is larger than the sum of its proper divisors (9409661).

28228971 is an equidigital number, since it uses as much as digits as its factorization.

28228971 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9409660.

The product of its digits is 32256, while the sum is 39.

The square root of 28228971 is about 5313.0942961705. The cubic root of 28228971 is about 304.4843782851.

The spelling of 28228971 in words is "twenty-eight million, two hundred twenty-eight thousand, nine hundred seventy-one".