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13440 = 27357
BaseRepresentation
bin11010010000000
3200102210
43102000
5412230
6142120
754120
oct32200
920383
1013440
11a109
127940
13616b
144c80
153eb0
hex3480

13440 has 64 divisors (see below), whose sum is σ = 48960. Its totient is φ = 3072.

The previous prime is 13421. The next prime is 13441. The reversal of 13440 is 4431.

Adding to 13440 its reverse (4431), we get a palindrome (17871).

Subtracting from 13440 its reverse (4431), we obtain a palindrome (9009).

It is a tau number, because it is divible by the number of its divisors (64).

It is a Harshad number since it is a multiple of its sum of digits (12).

It is an Ulam number.

It is a nialpdrome in base 8.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13441) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1917 + ... + 1923.

It is an arithmetic number, because the mean of its divisors is an integer number (765).

213440 is an apocalyptic number.

13440 is a gapful number since it is divisible by the number (10) 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 13440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24480).

13440 is an abundant number, since it is smaller than the sum of its proper divisors (35520).

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

13440 is an equidigital number, since it uses as much as digits as its factorization.

13440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29 (or 17 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 12.

The square root of 13440 is about 115.9310139695. The cubic root of 13440 is about 23.7756878111.

The spelling of 13440 in words is "thirteen thousand, four hundred forty".

Divisors: 1 2 3 4 5 6 7 8 10 12 14 15 16 20 21 24 28 30 32 35 40 42 48 56 60 64 70 80 84 96 105 112 120 128 140 160 168 192 210 224 240 280 320 336 384 420 448 480 560 640 672 840 896 960 1120 1344 1680 1920 2240 2688 3360 4480 6720 13440