28133280 has 144 divisors (see below), whose sum is σ = 109759104. Its totient is φ = 6428160.

The previous prime is 28133267. The next prime is 28133291. The reversal of 28133280 is 8233182.

28133280 = T₃₈₅ + T₃₈₆ + ... + T₆₀₈.

It is a tau number, because it is divible by the number of its divisors (144).

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 8685 + ... + 11475.

It is an arithmetic number, because the mean of its divisors is an integer number (762216).

Almost surely, 2^28133280 is an apocalyptic number.

28133280 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 28133280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (54879552).

28133280 is an abundant number, since it is smaller than the sum of its proper divisors (81625824).

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

28133280 is a wasteful number, since it uses less digits than its factorization.

28133280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2819 (or 2808 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 27.

The square root of 28133280 is about 5304.0814473385. The cubic root of 28133280 is about 304.1399401883.

The spelling of 28133280 in words is "twenty-eight million, one hundred thirty-three thousand, two hundred eighty".