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217280 = 265797
BaseRepresentation
bin110101000011000000
3102001001102
4311003000
523423110
64353532
71563320
oct650300
9361042
10217280
11139278
12a58a8
1377b8b
1459280
15445a5
hex350c0

217280 has 56 divisors (see below), whose sum is σ = 597408. Its totient is φ = 73728.

The previous prime is 217271. The next prime is 217307. The reversal of 217280 is 82712.

It is a tau number, because it is divible by the number of its divisors (56).

It is a Harshad number since it is a multiple of its sum of digits (20).

It is an unprimeable number.

217280 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2192 + ... + 2288.

It is an arithmetic number, because the mean of its divisors is an integer number (10668).

2217280 is an apocalyptic number.

217280 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 217280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (298704).

217280 is an abundant number, since it is smaller than the sum of its proper divisors (380128).

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

217280 is an equidigital number, since it uses as much as digits as its factorization.

217280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 121 (or 111 counting only the distinct ones).

The product of its (nonzero) digits is 224, while the sum is 20.

The square root of 217280 is about 466.1330282226. The cubic root of 217280 is about 60.1182851756.

Adding to 217280 its reverse (82712), we get a palindrome (299992).

The spelling of 217280 in words is "two hundred seventeen thousand, two hundred eighty".

Divisors: 1 2 4 5 7 8 10 14 16 20 28 32 35 40 56 64 70 80 97 112 140 160 194 224 280 320 388 448 485 560 679 776 970 1120 1358 1552 1940 2240 2716 3104 3395 3880 5432 6208 6790 7760 10864 13580 15520 21728 27160 31040 43456 54320 108640 217280