28123228 has 12 divisors (see below), whose sum is σ = 56246512. Its totient is φ = 12052800.

The previous prime is 28123213. The next prime is 28123229. The reversal of 28123228 is 82232182.

28123228 is an admirable number.

It is a Harshad number since it is a multiple of its sum of digits (28), and also a Moran number because the ratio is a prime number: 1004401 = 28123228 / (2 + 8 + 1 + 2 + 3 + 2 + 2 + 8).

It is a junction number, because it is equal to n+sod(n) for n = 28123196 and 28123205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28123229) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 502173 + ... + 502228.

Almost surely, 2^28123228 is an apocalyptic number.

28123228 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

28123228 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

28123228 is a wasteful number, since it uses less digits than its factorization.

28123228 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1004412 (or 1004410 counting only the distinct ones).

The product of its digits is 3072, while the sum is 28.

The square root of 28123228 is about 5303.1337905054. The cubic root of 28123228 is about 304.1037128819.

It can be divided in two parts, 281232 and 28, that multiplied together give a triangular number (7874496 = T₃₉₆₈).

The spelling of 28123228 in words is "twenty-eight million, one hundred twenty-three thousand, two hundred twenty-eight".