21143 has 2 divisors, whose sum is σ = 21144.
Its totient is φ = 21142.
The previous prime is 21139. The next prime is 21149. The reversal of 21143 is 34112.
Adding to 21143 its reverse (34112), we get a palindrome (55255).
It can be divided in two parts, 21 and 143, that multiplied together give a palindrome (3003).
It is a happy number.
It is a weak prime.
It is a cyclic number.
It is not a de Polignac number, because 21143 - 22 = 21139 is a prime.
It is a Chen prime.
It is a congruent number.
It is not a weakly prime, because it can be changed into another prime (21149) by changing a digit.
It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10571 + 10572.
It is an arithmetic number, because the mean of its divisors is an integer number (10572).
221143 is an apocalyptic number.
21143 is a deficient number, since it is larger than the sum of its proper divisors (1).
21143 is an equidigital number, since it uses as much as digits as its factorization.
21143 is an evil number, because the sum of its binary digits is even.
The product of its digits is 24, while the sum is 11.
The square root of 21143 is about 145.4063272351.
The cubic root of 21143 is about 27.6517233540.
The spelling of 21143 in words is "twenty-one thousand, one hundred forty-three", and thus it is an iban number.