28840028 has 36 divisors (see below), whose sum is σ = 59036040. Its totient is φ = 12291552.

The previous prime is 28840027. The next prime is 28840033. The reversal of 28840028 is 82004882.

It is a junction number, because it is equal to n+sod(n) for n = 28839976 and 28840003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28840027) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 52451 + ... + 52997.

It is an arithmetic number, because the mean of its divisors is an integer number (1639890).

Almost surely, 2^28840028 is an apocalyptic number.

28840028 is a gapful number since it is divisible by the number (28) 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 28840028, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29518020).

28840028 is an abundant number, since it is smaller than the sum of its proper divisors (30196012).

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

28840028 is a wasteful number, since it uses less digits than its factorization.

28840028 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 834 (or 825 counting only the distinct ones).

The product of its (nonzero) digits is 8192, while the sum is 32.

The square root of 28840028 is about 5370.2912397746. The cubic root of 28840028 is about 306.6657157080.

The spelling of 28840028 in words is "twenty-eight million, eight hundred forty thousand, twenty-eight".