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18120240 = 243358389
BaseRepresentation
bin100010100011…
…1111000110000
31021002121022000
41011013320300
514114321430
61444214000
7310006455
oct105077060
937077260
1018120240
11a257006
12609a300
1339a5948
14259982c
1518cde60
hex1147e30

18120240 has 80 divisors (see below), whose sum is σ = 62421600. Its totient is φ = 4831488.

The previous prime is 18120229. The next prime is 18120241. The reversal of 18120240 is 4202181.

It is a tau number, because it is divible by the number of its divisors (80).

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

It is not an unprimeable number, because it can be changed into a prime (18120241) 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 15 ways as a sum of consecutive naturals, for example, 2035 + ... + 6354.

It is an arithmetic number, because the mean of its divisors is an integer number (780270).

Almost surely, 218120240 is an apocalyptic number.

18120240 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18120240 is an abundant number, since it is smaller than the sum of its proper divisors (44301360).

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

18120240 is a wasteful number, since it uses less digits than its factorization.

18120240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8411 (or 8399 counting only the distinct ones).

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

The square root of 18120240 is about 4256.7875211244. The cubic root of 18120240 is about 262.6563965969.

The spelling of 18120240 in words is "eighteen million, one hundred twenty thousand, two hundred forty".

Divisors: 1 2 3 4 5 6 8 9 10 12 15 16 18 20 24 27 30 36 40 45 48 54 60 72 80 90 108 120 135 144 180 216 240 270 360 432 540 720 1080 2160 8389 16778 25167 33556 41945 50334 67112 75501 83890 100668 125835 134224 151002 167780 201336 226503 251670 302004 335560 377505 402672 453006 503340 604008 671120 755010 906012 1006680 1132515 1208016 1510020 1812024 2013360 2265030 3020040 3624048 4530060 6040080 9060120 18120240