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15680 = 26572
BaseRepresentation
bin11110101000000
3210111202
43311000
51000210
6200332
763500
oct36500
923452
1015680
1110865
1290a8
1371a2
145a00
1549a5
hex3d40

15680 has 42 divisors (see below), whose sum is σ = 43434. Its totient is φ = 5376.

The previous prime is 15679. The next prime is 15683. The reversal of 15680 is 8651.

It can be written as a sum of positive squares in only one way, i.e., 12544 + 3136 = 112^2 + 56^2 .

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

It is a nialpdrome in base 4.

It is a zygodrome in base 4.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (15683) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 2237 + ... + 2243.

215680 is an apocalyptic number.

15680 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 15680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21717).

15680 is an abundant number, since it is smaller than the sum of its proper divisors (27754).

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

15680 is an equidigital number, since it uses as much as digits as its factorization.

It is an anagram of its base 11 representation: 15680 = (10865)11.

15680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31 (or 14 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 20.

The square root of 15680 is about 125.2198067400. The cubic root of 15680 is about 25.0292989827.

Multiplying 15680 by its sum of digits (20), we get a square (313600 = 5602).

15680 divided by its sum of digits (20) gives a square (784 = 282).

The spelling of 15680 in words is "fifteen thousand, six hundred eighty".