21486 has 8 divisors (see below), whose sum is σ = 42984. Its totient is φ = 7160.
The previous prime is 21481. The next prime is 21487. The reversal of 21486 is 68412.
21486 is nontrivially palindromic in base 9.
It is a sphenic number, since it is the product of 3 distinct primes.
21486 is an admirable number.
It is a congruent number.
It is not an unprimeable number, because it can be changed into a prime (21481) by changing a digit.
It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1785 + ... + 1796.
It is an arithmetic number, because the mean of its divisors is an integer number (5373).
221486 is an apocalyptic number.
21486 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 (21492).
21486 is a wasteful number, since it uses less digits than its factorization.
21486 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 3586.
The product of its digits is 384, while the sum is 21.
The square root of 21486 is about 146.5810356083. The cubic root of 21486 is about 27.8004520051.
Adding to 21486 its reverse (68412), we get a palindrome (89898).
It can be divided in two parts, 214 and 86, that added together give a triangular number (300 = T24).
The spelling of 21486 in words is "twenty-one thousand, four hundred eighty-six".
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