28133380 has 48 divisors (see below), whose sum is σ = 66044160. Its totient is φ = 9977600.

The previous prime is 28133353. The next prime is 28133381. The reversal of 28133380 is 8333182.

It is a hoax number, since the sum of its digits (28) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28133381) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7461 + ... + 10579.

It is an arithmetic number, because the mean of its divisors is an integer number (1375920).

Almost surely, 2^28133380 is an apocalyptic number.

28133380 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 28133380, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33022080).

28133380 is an abundant number, since it is smaller than the sum of its proper divisors (37910780).

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

28133380 is a wasteful number, since it uses less digits than its factorization.

28133380 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3180 (or 3178 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 28.

The square root of 28133380 is about 5304.0908740330. The cubic root of 28133380 is about 304.1403005439.

The spelling of 28133380 in words is "twenty-eight million, one hundred thirty-three thousand, three hundred eighty".