28187520 has 128 divisors (see below), whose sum is σ = 91873440. Its totient is φ = 7348224.

The previous prime is 28187491. The next prime is 28187527. The reversal of 28187520 is 2578182.

It is a tau number, because it is divible by the number of its divisors (128).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28187527) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 101622 + ... + 101898.

Almost surely, 2^28187520 is an apocalyptic number.

28187520 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 28187520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (45936720).

28187520 is an abundant number, since it is smaller than the sum of its proper divisors (63685920).

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

28187520 is a wasteful number, since it uses less digits than its factorization.

28187520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 352 (or 340 counting only the distinct ones).

The product of its (nonzero) digits is 8960, while the sum is 33.

The square root of 28187520 is about 5309.1920289249. The cubic root of 28187520 is about 304.3352718394.

The spelling of 28187520 in words is "twenty-eight million, one hundred eighty-seven thousand, five hundred twenty".