28133680 has 80 divisors (see below), whose sum is σ = 69995520. Its totient is φ = 10485504.

The previous prime is 28133671. The next prime is 28133687. The reversal of 28133680 is 8633182.

It is a tau number, because it is divible by the number of its divisors (80).

It is not an unprimeable number, because it can be changed into a prime (28133687) 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 15 ways as a sum of consecutive naturals, for example, 126049 + ... + 126271.

It is an arithmetic number, because the mean of its divisors is an integer number (874944).

Almost surely, 2^28133680 is an apocalyptic number.

28133680 is a gapful number since it is divisible by the number (20) 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 28133680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34997760).

28133680 is an abundant number, since it is smaller than the sum of its proper divisors (41861840).

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

28133680 is a wasteful number, since it uses less digits than its factorization.

28133680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 338 (or 332 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 31.

The square root of 28133680 is about 5304.1191540161. The cubic root of 28133680 is about 304.1413816057.

The spelling of 28133680 in words is "twenty-eight million, one hundred thirty-three thousand, six hundred eighty".