28009020 has 96 divisors (see below), whose sum is σ = 85377600. Its totient is φ = 6819840.

The previous prime is 28009019. The next prime is 28009043. The reversal of 28009020 is 2090082.

It is a congruent number.

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 31 ways as a sum of consecutive naturals, for example, 116100 + ... + 116340.

It is an arithmetic number, because the mean of its divisors is an integer number (889350).

Almost surely, 2^28009020 is an apocalyptic number.

28009020 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 28009020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (42688800).

28009020 is an abundant number, since it is smaller than the sum of its proper divisors (57368580).

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

28009020 is a wasteful number, since it uses less digits than its factorization.

28009020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 415 (or 413 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 21.

The square root of 28009020 is about 5292.3548633855. The cubic root of 28009020 is about 303.6915008684.

The spelling of 28009020 in words is "twenty-eight million, nine thousand, twenty".