28507788 has 72 divisors (see below), whose sum is σ = 75624640. Its totient is φ = 9389520.

The previous prime is 28507757. The next prime is 28507789. The reversal of 28507788 is 88770582.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (28507789) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 135003 + ... + 135213.

Almost surely, 2^28507788 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28507788, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37812320).

28507788 is an abundant number, since it is smaller than the sum of its proper divisors (47116852).

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

28507788 is a wasteful number, since it uses less digits than its factorization.

28507788 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 369 (or 355 counting only the distinct ones).

The product of its (nonzero) digits is 250880, while the sum is 45.

The square root of 28507788 is about 5339.2684892221. The cubic root of 28507788 is about 305.4835579470.

The spelling of 28507788 in words is "twenty-eight million, five hundred seven thousand, seven hundred eighty-eight".