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28789880 = 2357229449
BaseRepresentation
bin110110111010…
…0110001111000
32000011200021212
41231310301320
524332234010
62505022252
7466465340
oct155646170
960150255
1028789880
1115284299
129784988
135c70242
143b75d20
1527da505
hex1b74c78

28789880 has 64 divisors (see below), whose sum is σ = 74520000. Its totient is φ = 9805824.

The previous prime is 28789879. The next prime is 28789889. The reversal of 28789880 is 8898782.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28789889) 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, 63896 + ... + 64344.

It is an arithmetic number, because the mean of its divisors is an integer number (1164375).

Almost surely, 228789880 is an apocalyptic number.

28789880 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 28789880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37260000).

28789880 is an abundant number, since it is smaller than the sum of its proper divisors (45730120).

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

28789880 is a wasteful number, since it uses less digits than its factorization.

28789880 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 696 (or 692 counting only the distinct ones).

The product of its (nonzero) digits is 516096, while the sum is 50.

The square root of 28789880 is about 5365.6201878254. The cubic root of 28789880 is about 306.4878657353.

The spelling of 28789880 in words is "twenty-eight million, seven hundred eighty-nine thousand, eight hundred eighty".

Divisors: 1 2 4 5 7 8 10 14 20 28 35 40 56 70 140 229 280 449 458 898 916 1145 1603 1796 1832 2245 2290 3143 3206 3592 4490 4580 6286 6412 8015 8980 9160 12572 12824 15715 16030 17960 25144 31430 32060 62860 64120 102821 125720 205642 411284 514105 719747 822568 1028210 1439494 2056420 2878988 3598735 4112840 5757976 7197470 14394940 28789880