28563820 has 24 divisors (see below), whose sum is σ = 61118064. Its totient is φ = 11209536.

The previous prime is 28563817. The next prime is 28563823. The reversal of 28563820 is 2836582.

It is an interprime number because it is at equal distance from previous prime (28563817) and next prime (28563823).

It is not an unprimeable number, because it can be changed into a prime (28563823) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12414 + ... + 14533.

It is an arithmetic number, because the mean of its divisors is an integer number (2546586).

Almost surely, 2^28563820 is an apocalyptic number.

28563820 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28563820 is an abundant number, since it is smaller than the sum of its proper divisors (32554244).

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

28563820 is a wasteful number, since it uses less digits than its factorization.

28563820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27009 (or 27007 counting only the distinct ones).

The product of its (nonzero) digits is 23040, while the sum is 34.

The square root of 28563820 is about 5344.5130741724. The cubic root of 28563820 is about 305.6835694031.

The spelling of 28563820 in words is "twenty-eight million, five hundred sixty-three thousand, eight hundred twenty".