28945728 has 112 divisors (see below), whose sum is σ = 97292160. Its totient is φ = 8266752.

The previous prime is 28945727. The next prime is 28945739. The reversal of 28945728 is 82754982.

It is a tau number, because it is divible by the number of its divisors (112).

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28945727) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10900 + ... + 13292.

It is an arithmetic number, because the mean of its divisors is an integer number (868680).

Almost surely, 2^28945728 is an apocalyptic number.

28945728 is a gapful number since it is divisible by the number (28) 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 28945728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (48646080).

28945728 is an abundant number, since it is smaller than the sum of its proper divisors (68346432).

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

28945728 is a wasteful number, since it uses less digits than its factorization.

28945728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2421 (or 2405 counting only the distinct ones).

The product of its digits is 322560, while the sum is 45.

The square root of 28945728 is about 5380.1234186587. The cubic root of 28945728 is about 307.0399068184.

The spelling of 28945728 in words is "twenty-eight million, nine hundred forty-five thousand, seven hundred twenty-eight".