28808640 has 168 divisors, whose sum is σ = 113324640. Its totient is φ = 6580224.

The previous prime is 28808623. The next prime is 28808651. The reversal of 28808640 is 4680882.

28808640 is a `hidden beast` number, since 2 + 8 + 8 + 0 + 8 + 640 = 666.

It is a tau number, because it is divible by the number of its divisors (168).

It is a Harshad number since it is a multiple of its sum of digits (36).

28808640 is a modest number, since divided by 8640 gives 2880 as remainder.

It is a junction number, because it is equal to n+sod(n) for n = 28808595 and 28808604.

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 23 ways as a sum of consecutive naturals, for example, 19446 + ... + 20874.

Almost surely, 2^28808640 is an apocalyptic number.

28808640 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 28808640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (56662320).

28808640 is an abundant number, since it is smaller than the sum of its proper divisors (84516000).

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

28808640 is a wasteful number, since it uses less digits than its factorization.

28808640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1459 (or 1446 counting only the distinct ones).

The product of its (nonzero) digits is 24576, while the sum is 36.

The square root of 28808640 is about 5367.3680701066. The cubic root of 28808640 is about 306.5544222700.

The spelling of 28808640 in words is "twenty-eight million, eight hundred eight thousand, six hundred forty".