12705 has 24 divisors (see below), whose sum is σ = 25536. Its totient is φ = 5280.
The previous prime is 12703. The next prime is 12713. The reversal of 12705 is 50721.
It is a happy number.
It is not a de Polignac number, because 12705 - 21 = 12703 is a prime.
It is a super-2 number, since 2×127052 = 322834050, which contains 22 as substring.
It is a Harshad number since it is a multiple of its sum of digits (15).
It is an Ulam number.
It is an alternating number because its digits alternate between odd and even.
It is a Curzon number.
It is a nialpdrome in base 11.
It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 12705.
It is not an unprimeable number, because it can be changed into a prime (12703) by changing a digit.
It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1150 + ... + 1160.
It is an arithmetic number, because the mean of its divisors is an integer number (1064).
212705 is an apocalyptic number.
12705 is a gapful number since it is divisible by the number (15) formed by its first and last digit.
It is an amenable number.
12705 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.
It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.
It is a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (12768).
12705 is a wasteful number, since it uses less digits than its factorization.
12705 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 37 (or 26 counting only the distinct ones).
The product of its (nonzero) digits is 70, while the sum is 15.
The square root of 12705 is about 112.7164584256. The cubic root of 12705 is about 23.3341269571.
Adding to 12705 its sum of digits (15), we get a triangular number (12720 = T159).
It can be divided in two parts, 1270 and 5, that added together give a triangular number (1275 = T50).
The spelling of 12705 in words is "twelve thousand, seven hundred five".
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