28387520 has 224 divisors, whose sum is σ = 87782400. Its totient is φ = 8515584.

The previous prime is 28387517. The next prime is 28387523. The reversal of 28387520 is 2578382.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (28387517) and next prime (28387523).

It is a tau number, because it is divible by the number of its divisors (224).

It is a Harshad number since it is a multiple of its sum of digits (35).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28387523) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 978866 + ... + 978894.

Almost surely, 2^28387520 is an apocalyptic number.

28387520 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 28387520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (43891200).

28387520 is an abundant number, since it is smaller than the sum of its proper divisors (59394880).

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

28387520 is a wasteful number, since it uses less digits than its factorization.

28387520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 95 (or 85 counting only the distinct ones).

The product of its (nonzero) digits is 26880, while the sum is 35.

The square root of 28387520 is about 5327.9939939906. The cubic root of 28387520 is about 305.0533634121.

The spelling of 28387520 in words is "twenty-eight million, three hundred eighty-seven thousand, five hundred twenty".