19541 has 2 divisors, whose sum is σ = 19542.
Its totient is φ = 19540.
The previous prime is 19531. The next prime is 19543. The reversal of 19541 is 14591.
Subtracting from 19541 its reverse (14591), we obtain a triangular number (4950 = T99).
It is a strong prime.
It can be written as a sum of positive squares in only one way, i.e., 14641 + 4900 = 121^2 + 70^2
It is an emirp because it is prime and its reverse (14591) is a distict prime.
It is a cyclic number.
It is not a de Polignac number, because 19541 - 26 = 19477 is a prime.
Together with 19543, it forms a pair of twin primes.
It is a Chen prime.
It is a congruent number.
It is not a weakly prime, because it can be changed into another prime (19543) 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 as a sum of consecutive naturals, namely, 9770 + 9771.
It is an arithmetic number, because the mean of its divisors is an integer number (9771).
219541 is an apocalyptic number.
It is an amenable number.
19541 is a deficient number, since it is larger than the sum of its proper divisors (1).
19541 is an equidigital number, since it uses as much as digits as its factorization.
19541 is an odious number, because the sum of its binary digits is odd.
The product of its digits is 180, while the sum is 20.
The square root of 19541 is about 139.7891269019.
The cubic root of 19541 is about 26.9349141041.
The spelling of 19541 in words is "nineteen thousand, five hundred forty-one".