28505376 has 72 divisors (see below), whose sum is σ = 83881980. Its totient is φ = 9171456.

The previous prime is 28505341. The next prime is 28505381. The reversal of 28505376 is 67350582.

28505376 is a `hidden beast` number, since 285 + 0 + 5 + 376 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 26255376 + 2250000 = 5124^2 + 1500^2 .

It is a tau number, because it is divible by the number of its divisors (72).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a self number, because there is not a number n which added to its sum of digits gives 28505376.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 6646 + ... + 10058.

Almost surely, 2^28505376 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 28505376, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (41940990).

28505376 is an abundant number, since it is smaller than the sum of its proper divisors (55376604).

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

28505376 is a wasteful number, since it uses less digits than its factorization.

28505376 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3458 (or 3447 counting only the distinct ones).

The product of its (nonzero) digits is 50400, while the sum is 36.

The square root of 28505376 is about 5339.0426108058. The cubic root of 28505376 is about 305.4749422063.

The spelling of 28505376 in words is "twenty-eight million, five hundred five thousand, three hundred seventy-six".