28280420 has 48 divisors (see below), whose sum is σ = 68759040. Its totient is φ = 9569664.

The previous prime is 28280353. The next prime is 28280431. The reversal of 28280420 is 2408282.

It is a self number, because there is not a number n which added to its sum of digits gives 28280420.

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 15 ways as a sum of consecutive naturals, for example, 9782 + ... + 12338.

It is an arithmetic number, because the mean of its divisors is an integer number (1432480).

Almost surely, 2^28280420 is an apocalyptic number.

28280420 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 28280420, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34379520).

28280420 is an abundant number, since it is smaller than the sum of its proper divisors (40478620).

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

28280420 is a wasteful number, since it uses less digits than its factorization.

28280420 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2652 (or 2650 counting only the distinct ones).

The product of its (nonzero) digits is 2048, while the sum is 26.

The square root of 28280420 is about 5317.9338092910. The cubic root of 28280420 is about 304.6692463928.

The spelling of 28280420 in words is "twenty-eight million, two hundred eighty thousand, four hundred twenty".