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28728760 = 23519103367
BaseRepresentation
bin110110110010…
…1110110111000
32000001120110011
41231211312320
524323310020
62503431304
7466122214
oct155456670
960046404
1028728760
1115242385
129755534
135c4b488
143b5b944
1527c735a
hex1b65db8

28728760 has 64 divisors (see below), whose sum is σ = 68889600. Its totient is φ = 10751616.

The previous prime is 28728731. The next prime is 28728769. The reversal of 28728760 is 6782782.

It is a super-2 number, since 2×287287602 = 1650683302275200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (40).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28728769) 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, 78097 + ... + 78463.

It is an arithmetic number, because the mean of its divisors is an integer number (1076400).

Almost surely, 228728760 is an apocalyptic number.

28728760 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 28728760, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34444800).

28728760 is an abundant number, since it is smaller than the sum of its proper divisors (40160840).

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

28728760 is a wasteful number, since it uses less digits than its factorization.

28728760 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 500 (or 496 counting only the distinct ones).

The product of its (nonzero) digits is 75264, while the sum is 40.

The square root of 28728760 is about 5359.9216412183. The cubic root of 28728760 is about 306.2708240734.

The spelling of 28728760 in words is "twenty-eight million, seven hundred twenty-eight thousand, seven hundred sixty".

Divisors: 1 2 4 5 8 10 19 20 38 40 76 95 103 152 190 206 367 380 412 515 734 760 824 1030 1468 1835 1957 2060 2936 3670 3914 4120 6973 7340 7828 9785 13946 14680 15656 19570 27892 34865 37801 39140 55784 69730 75602 78280 139460 151204 189005 278920 302408 378010 718219 756020 1436438 1512040 2872876 3591095 5745752 7182190 14364380 28728760