21267 has 12 divisors (see below), whose sum is σ = 32760.
Its totient is φ = 13248.
The previous prime is 21247. The next prime is 21269. The reversal of 21267 is 76212.
It is a happy number.
It is not a de Polignac number, because 21267 - 27 = 21139 is a prime.
It is not an unprimeable number, because it can be changed into a prime (21269) by changing a digit.
It is a pernicious number, because its binary representation contains a prime number (7) of ones.
It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 84 + ... + 222.
It is an arithmetic number, because the mean of its divisors is an integer number (2730).
221267 is an apocalyptic number.
21267 is a deficient number, since it is larger than the sum of its proper divisors (11493).
21267 is a wasteful number, since it uses less digits than its factorization.
21267 is an odious number, because the sum of its binary digits is odd.
The sum of its prime factors is 162 (or 159 counting only the distinct ones).
The product of its digits is 168, while the sum is 18.
The square root of 21267 is about 145.8320952328.
The cubic root of 21267 is about 27.7056755260.
Adding to 21267 its reverse (76212), we get a palindrome (97479).
Subtracting 21267 from its reverse (76212), we obtain a palindrome (54945).
The spelling of 21267 in words is "twenty-one thousand, two hundred sixty-seven".