28563840 has 320 divisors, whose sum is σ = 111078000. Its totient is φ = 6967296.

The previous prime is 28563823. The next prime is 28563853. The reversal of 28563840 is 4836582.

It is a tau number, because it is divible by the number of its divisors (320).

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 = 28563795 and 28563804.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 984946 + ... + 984974.

Almost surely, 2^28563840 is an apocalyptic number.

28563840 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 28563840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (55539000).

28563840 is an abundant number, since it is smaller than the sum of its proper divisors (82514160).

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

28563840 is a wasteful number, since it uses less digits than its factorization.

28563840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 79 (or 58 counting only the distinct ones).

The product of its (nonzero) digits is 46080, while the sum is 36.

The square root of 28563840 is about 5344.5149452499. The cubic root of 28563840 is about 305.6836407482.

It can be divided in two parts, 28563 and 840, that added together give a triangular number (29403 = T₂₄₂).

The spelling of 28563840 in words is "twenty-eight million, five hundred sixty-three thousand, eight hundred forty".