28089920 has 56 divisors (see below), whose sum is σ = 68552568. Its totient is φ = 10956800.

The previous prime is 28089917. The next prime is 28089931. The reversal of 28089920 is 2998082.

It can be written as a sum of positive squares in 4 ways, for example, as 2849344 + 25240576 = 1688^2 + 5024^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12050 + ... + 14190.

It is an arithmetic number, because the mean of its divisors is an integer number (1224153).

Almost surely, 2^28089920 is an apocalyptic number.

28089920 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 28089920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34276284).

28089920 is an abundant number, since it is smaller than the sum of its proper divisors (40462648).

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

28089920 is a wasteful number, since it uses less digits than its factorization.

28089920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2199 (or 2189 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 38.

The square root of 28089920 is about 5299.9924528248. The cubic root of 28089920 is about 303.9836094579.

The spelling of 28089920 in words is "twenty-eight million, eighty-nine thousand, nine hundred twenty".