28067840 has 48 divisors (see below), whose sum is σ = 67370940. Its totient is φ = 11223040.

The previous prime is 28067839. The next prime is 28067849. The reversal of 28067840 is 4876082.

It can be written as a sum of positive squares in 2 ways, for example, as 27206656 + 861184 = 5216^2 + 928^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 28067840.

It is not an unprimeable number, because it can be changed into a prime (28067849) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8870 + ... + 11610.

Almost surely, 2^28067840 is an apocalyptic number.

28067840 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 28067840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33685470).

28067840 is an abundant number, since it is smaller than the sum of its proper divisors (39303100).

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

28067840 is an equidigital number, since it uses as much as digits as its factorization.

28067840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2768 (or 2748 counting only the distinct ones).

The product of its (nonzero) digits is 21504, while the sum is 35.

The square root of 28067840 is about 5297.9090214914. The cubic root of 28067840 is about 303.9039401020.

The spelling of 28067840 in words is "twenty-eight million, sixty-seven thousand, eight hundred forty".