28088640 has 112 divisors (see below), whose sum is σ = 99120960. Its totient is φ = 7488000.

The previous prime is 28088639. The next prime is 28088647. The reversal of 28088640 is 4688082.

28088640 is a `hidden beast` number, since 2 + 8 + 0 + 8 + 8 + 640 = 666.

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

It is a junction number, because it is equal to n+sod(n) for n = 28088595 and 28088604.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28088647) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7015 + ... + 10265.

Almost surely, 2^28088640 is an apocalyptic number.

28088640 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 28088640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (49560480).

28088640 is an abundant number, since it is smaller than the sum of its proper divisors (71032320).

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

28088640 is a wasteful number, since it uses less digits than its factorization.

28088640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3277 (or 3261 counting only the distinct ones).

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

The square root of 28088640 is about 5299.8716965602. The cubic root of 28088640 is about 303.9789920848.

The spelling of 28088640 in words is "twenty-eight million, eighty-eight thousand, six hundred forty".