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28800000 = 2103255

28800000 has 198 divisors, whose sum is σ = 103942566. Its totient is φ = 7680000.

The previous prime is 28799963. The next prime is 28800001. The reversal of 28800000 is 882.

Adding to 28800000 its reverse (882), we get a palindrome (28800882).

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 can be written as a sum of positive squares in 3 ways, for example, as 13307904 + 15492096 = 3648^2 + 3936^2 .

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 congruent number.

It is not an unprimeable number, because it can be changed into a prime (28800001) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 5759998 + ... + 5760002.

Almost surely, 228800000 is an apocalyptic number.

28800000 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 28800000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (51971283).

28800000 is an abundant number, since it is smaller than the sum of its proper divisors (75142566).

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

28800000 is an frugal number, since it uses more digits than its factorization.

28800000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 51 (or 10 counting only the distinct ones).

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

The square root of 28800000 is about 5366.5631459995. The cubic root of 28800000 is about 306.5237729574.

The spelling of 28800000 in words is "twenty-eight million, eight hundred thousand".