28563864 has 96 divisors (see below), whose sum is σ = 84214080. Its totient is φ = 8049216.

The previous prime is 28563853. The next prime is 28563877. The reversal of 28563864 is 46836582.

It is a super-2 number, since 2×28563864² = 1631788653220992, which contains 22 as substring.

It is a Smith number, since the sum of its digits (42) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 125719 + ... + 125945.

It is an arithmetic number, because the mean of its divisors is an integer number (877230).

Almost surely, 2^28563864 is an apocalyptic number.

28563864 is a gapful number since it is divisible by the number (24) 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 28563864, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (42107040).

28563864 is an abundant number, since it is smaller than the sum of its proper divisors (55650216).

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

28563864 is a wasteful number, since it uses less digits than its factorization.

28563864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 357 (or 346 counting only the distinct ones).

The product of its digits is 276480, while the sum is 42.

The square root of 28563864 is about 5344.5171905421. The cubic root of 28563864 is about 305.6837263624.

The spelling of 28563864 in words is "twenty-eight million, five hundred sixty-three thousand, eight hundred sixty-four".