28912128 has 80 divisors (see below), whose sum is σ = 88059840. Its totient is φ = 8257536.

The previous prime is 28912099. The next prime is 28912151. The reversal of 28912128 is 82121982.

It is a Cunningham number, because it is equal to 5377²-1.

It is a super-2 number, since 2×28912128² = 1671822290976768, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9408 + ... + 12096.

It is an arithmetic number, because the mean of its divisors is an integer number (1100748).

Almost surely, 2^28912128 is an apocalyptic number.

28912128 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28912128, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (44029920).

28912128 is an abundant number, since it is smaller than the sum of its proper divisors (59147712).

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

28912128 is an equidigital number, since it uses as much as digits as its factorization.

28912128 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2717 (or 2701 counting only the distinct ones).

The product of its digits is 4608, while the sum is 33.

The square root of 28912128 is about 5376.9999070113. Note that the first 4 decimals coincide. The cubic root of 28912128 is about 306.9210575564.

The spelling of 28912128 in words is "twenty-eight million, nine hundred twelve thousand, one hundred twenty-eight".