28324428 has 48 divisors (see below), whose sum is σ = 72938880. Its totient is φ = 8483200.

The previous prime is 28324411. The next prime is 28324507. The reversal of 28324428 is 82442382.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10543 + ... + 12953.

It is an arithmetic number, because the mean of its divisors is an integer number (1519560).

Almost surely, 2^28324428 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28324428, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36469440).

28324428 is an abundant number, since it is smaller than the sum of its proper divisors (44614452).

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

28324428 is a wasteful number, since it uses less digits than its factorization.

28324428 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2518 (or 2516 counting only the distinct ones).

The product of its digits is 24576, while the sum is 33.

The square root of 28324428 is about 5322.0698980754. The cubic root of 28324428 is about 304.8271994382.

It can be divided in two parts, 2832 and 4428, that added together give a triangular number (7260 = T₁₂₀).

The spelling of 28324428 in words is "twenty-eight million, three hundred twenty-four thousand, four hundred twenty-eight".