28705536 has 72 divisors (see below), whose sum is σ = 84907760. Its totient is φ = 9566208.

The previous prime is 28705529. The next prime is 28705559. The reversal of 28705536 is 63550782.

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 nialpdrome in base 12.

It is a self number, because there is not a number n which added to its sum of digits gives 28705536.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4836 + ... + 8988.

Almost surely, 2^28705536 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 28705536, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (42453880).

28705536 is an abundant number, since it is smaller than the sum of its proper divisors (56202224).

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

28705536 is an equidigital number, since it uses as much as digits as its factorization.

28705536 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4178 (or 4158 counting only the distinct ones).

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

The square root of 28705536 is about 5357.7547536258. The cubic root of 28705536 is about 306.1882732181.

It can be divided in two parts, 28705 and 536, that added together give a square (29241 = 171²).

The spelling of 28705536 in words is "twenty-eight million, seven hundred five thousand, five hundred thirty-six".