28028520 has 192 divisors, whose sum is σ = 100835280. Its totient is φ = 6709248.

The previous prime is 28028509. The next prime is 28028527. The reversal of 28028520 is 2582082.

It can be written as a sum of positive squares in 8 ways, for example, as 2566404 + 25462116 = 1602^2 + 5046^2 .

It is a hoax number, since the sum of its digits (27) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28028527) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 247984 + ... + 248096.

Almost surely, 2^28028520 is an apocalyptic number.

28028520 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 28028520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (50417640).

28028520 is an abundant number, since it is smaller than the sum of its proper divisors (72806760).

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

28028520 is a wasteful number, since it uses less digits than its factorization.

28028520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 196 (or 189 counting only the distinct ones).

The product of its (nonzero) digits is 2560, while the sum is 27.

The square root of 28028520 is about 5294.1968229374. The cubic root of 28028520 is about 303.7619616282.

The spelling of 28028520 in words is "twenty-eight million, twenty-eight thousand, five hundred twenty".