28009280 has 56 divisors (see below), whose sum is σ = 71838312. Its totient is φ = 10340352.

The previous prime is 28009231. The next prime is 28009291. The reversal of 28009280 is 8290082.

It can be written as a sum of positive squares in 4 ways, for example, as 6031936 + 21977344 = 2456^2 + 4688^2 .

It is a super-2 number, since 2×28009280² = 1569039532236800, which contains 22 as substring.

It is a congruent number.

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, 794 + ... + 7526.

It is an arithmetic number, because the mean of its divisors is an integer number (1282827).

Almost surely, 2^28009280 is an apocalyptic number.

28009280 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 28009280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35919156).

28009280 is an abundant number, since it is smaller than the sum of its proper divisors (43829032).

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

28009280 is a wasteful number, since it uses less digits than its factorization.

28009280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6763 (or 6753 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 29.

The square root of 28009280 is about 5292.3794270630. The cubic root of 28009280 is about 303.6924405603.

The spelling of 28009280 in words is "twenty-eight million, nine thousand, two hundred eighty".