28840000 has 140 divisors (see below), whose sum is σ = 82523584. Its totient is φ = 9792000.

The previous prime is 28839991. The next prime is 28840001. The reversal of 28840000 is 4882.

It is a tau number, because it is divible by the number of its divisors (140).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28840001) 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 19 ways as a sum of consecutive naturals, for example, 279949 + ... + 280051.

Almost surely, 2^28840000 is an apocalyptic number.

28840000 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 28840000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (41261792).

28840000 is an abundant number, since it is smaller than the sum of its proper divisors (53683584).

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

28840000 is an equidigital number, since it uses as much as digits as its factorization.

28840000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 142 (or 117 counting only the distinct ones).

The product of its (nonzero) digits is 512, while the sum is 22.

The square root of 28840000 is about 5370.2886328390. The cubic root of 28840000 is about 306.6656164635.

Adding to 28840000 its reverse (4882), we get a palindrome (28844882).

The spelling of 28840000 in words is "twenty-eight million, eight hundred forty thousand".