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BaseRepresentation
bin111000010000000
31110111200
413002000
51410200
6341200
7146652
oct70200
943450
1028800
111a702
1214800
1310155
14a6d2
158800
hex7080

28800 has 72 divisors (see below), whose sum is σ = 102765. Its totient is φ = 7680.

The previous prime is 28793. The next prime is 28807. The reversal of 28800 is 882.

Subtracting from 28800 its sum of digits (18), we obtain a palindrome (28782).

Multipling 28800 by its sum of digits (18), we get a square (518400 = 7202).

28800 divided by its sum of digits (18) gives a square (1600 = 402).

Multipling 28800 by its product of nonzero digits (128), we get a square (3686400 = 19202).

28800 divided by its product of nonzero digits (128) gives a square (225 = 152).

Multipling 28800 by its reverse (882), we get a square (25401600 = 50402).

It can be divided in two parts, 28 and 800, that added together give a palindrome (828).

28800 = 73 + 83 + ... + 183.

It is a powerful number, because all its prime factors have an exponent greater than 1 and also an Achilles number because it is not a perfect power.

It is a Jordan-Polya number, since it can be written as (5!)2 ⋅ 2!.

It is an interprime number because it is at equal distance from previous prime (28793) and next prime (28807).

It can be written as a sum of positive squares in 2 ways, for example, as 28224 + 576 = 168^2 + 24^2 .

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

It is an ABA number since it can be written as A⋅BA, here for A=2, B=120.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a super Niven number, because it is divisible the sum of any subset of its (nonzero) digits.

It is a nialpdrome in base 15.

It is a zygodrome in base 15.

It is not an unprimeable number, because it can be changed into a prime (28807) by changing a digit.

28800 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 5758 + ... + 5762.

228800 is an apocalyptic number.

28800 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 28800

28800 is an abundant number, since it is smaller than the sum of its proper divisors (73965).

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

28800 is a wasteful number, since it uses less digits than its factorization.

28800 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30 (or 10 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 18.

The square root of 28800 is about 169.7056274848. The cubic root of 28800 is about 30.6523772957.

The spelling of 28800 in words is "twenty-eight thousand, eight hundred".