28813520 has 20 divisors (see below), whose sum is σ = 66991620. Its totient is φ = 11525376.

The previous prime is 28813517. The next prime is 28813523. The reversal of 28813520 is 2531882.

It is an interprime number because it is at equal distance from previous prime (28813517) and next prime (28813523).

It can be written as a sum of positive squares in 2 ways, for example, as 22543504 + 6270016 = 4748^2 + 2504^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28813523) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 180005 + ... + 180164.

It is an arithmetic number, because the mean of its divisors is an integer number (3349581).

Almost surely, 2^28813520 is an apocalyptic number.

28813520 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

28813520 is an abundant number, since it is smaller than the sum of its proper divisors (38178100).

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

28813520 is a wasteful number, since it uses less digits than its factorization.

28813520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 360182 (or 360176 counting only the distinct ones).

The product of its (nonzero) digits is 3840, while the sum is 29.

The square root of 28813520 is about 5367.8226498274. The cubic root of 28813520 is about 306.5717307478.

The spelling of 28813520 in words is "twenty-eight million, eight hundred thirteen thousand, five hundred twenty".