21433 has 2 divisors, whose sum is σ = 21434.
Its totient is φ = 21432.
The previous prime is 21419. The next prime is 21467. The reversal of 21433 is 33412.
Adding to 21433 its reverse (33412), we get a palindrome (54845).
It can be divided in two parts, 21 and 433, that added together give a palindrome (454).
It is a weak prime.
It can be written as a sum of positive squares in only one way, i.e., 13689 + 7744 = 117^2 + 88^2
It is a cyclic number.
It is not a de Polignac number, because 21433 - 25 = 21401 is a prime.
21433 is a lucky number.
It is not a weakly prime, because it can be changed into another prime (21493) by changing a digit.
It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10716 + 10717.
It is an arithmetic number, because the mean of its divisors is an integer number (10717).
221433 is an apocalyptic number.
It is an amenable number.
21433 is a deficient number, since it is larger than the sum of its proper divisors (1).
21433 is an equidigital number, since it uses as much as digits as its factorization.
21433 is an odious number, because the sum of its binary digits is odd.
The product of its digits is 72, while the sum is 13.
The square root of 21433 is about 146.4001366120.
The cubic root of 21433 is about 27.7775745170.
Note that the first 3 decimals are identical.
The spelling of 21433 in words is "twenty-one thousand, four hundred thirty-three".