28711228 has 24 divisors (see below), whose sum is σ = 61840352. Its totient is φ = 11358144.

The previous prime is 28711211. The next prime is 28711231. The reversal of 28711228 is 82211782.

It is a super-2 number, since 2×28711228² = 1648669226535968, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 28711228.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 39075 + ... + 39802.

Almost surely, 2^28711228 is an apocalyptic number.

28711228 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

28711228 is an abundant number, since it is smaller than the sum of its proper divisors (33129124).

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

28711228 is a wasteful number, since it uses less digits than its factorization.

28711228 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 78901 (or 78899 counting only the distinct ones).

The product of its digits is 3584, while the sum is 31.

The square root of 28711228 is about 5358.2859199561. The cubic root of 28711228 is about 306.2085098311.

The spelling of 28711228 in words is "twenty-eight million, seven hundred eleven thousand, two hundred twenty-eight".