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28385280 = 213325711
BaseRepresentation
bin110110001001…
…0000000000000
31222102010021200
41230102000000
524231312110
62452221200
7463161630
oct154220000
958363250
1028385280
1115028310
12960a800
135b5b031
143aac6c0
15275a6c0
hex1b12000

28385280 has 336 divisors, whose sum is σ = 122675904. Its totient is φ = 5898240.

The previous prime is 28385267. The next prime is 28385311. The reversal of 28385280 is 8258382.

It is a tau number, because it is divible by the number of its divisors (336).

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

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2580475 + ... + 2580485.

Almost surely, 228385280 is an apocalyptic number.

28385280 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 28385280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (61337952).

28385280 is an abundant number, since it is smaller than the sum of its proper divisors (94290624).

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

28385280 is a wasteful number, since it uses less digits than its factorization.

28385280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 55 (or 28 counting only the distinct ones).

The product of its (nonzero) digits is 30720, while the sum is 36.

The square root of 28385280 is about 5327.7837793965. The cubic root of 28385280 is about 305.0453394929.

It can be divided in two parts, 2838 and 5280, that added together give a palindrome (8118).

The spelling of 28385280 in words is "twenty-eight million, three hundred eighty-five thousand, two hundred eighty".