28689520 has 40 divisors (see below), whose sum is σ = 67808160. Its totient is φ = 11285760.

The previous prime is 28689499. The next prime is 28689527. The reversal of 28689520 is 2598682.

It is a tau number, because it is divible by the number of its divisors (40).

It is a Harshad number since it is a multiple of its sum of digits (40).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28689527) 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, 1941 + ... + 7819.

It is an arithmetic number, because the mean of its divisors is an integer number (1695204).

Almost surely, 2^28689520 is an apocalyptic number.

28689520 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 28689520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33904080).

28689520 is an abundant number, since it is smaller than the sum of its proper divisors (39118640).

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

28689520 is a wasteful number, since it uses less digits than its factorization.

28689520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5953 (or 5947 counting only the distinct ones).

The product of its (nonzero) digits is 69120, while the sum is 40.

The square root of 28689520 is about 5356.2598891391. The cubic root of 28689520 is about 306.1313176109.

The spelling of 28689520 in words is "twenty-eight million, six hundred eighty-nine thousand, five hundred twenty".