20533 has 2 divisors, whose sum is σ = 20534.
Its totient is φ = 20532.
The previous prime is 20521. The next prime is 20543. The reversal of 20533 is 33502.
It is the 59-th star number.
It is a strong prime.
It can be written as a sum of positive squares in only one way, i.e., 18769 + 1764 = 137^2 + 42^2
It is a cyclic number.
It is not a de Polignac number, because 20533 - 29 = 20021 is a prime.
It is equal to p2317 and since 20533 and 2317 have the same sum of digits, it is a Honaker prime.
It is a plaindrome in base 11.
It is a nialpdrome in base 12.
It is a congruent number.
It is not a weakly prime, because it can be changed into another prime (20543) by changing a digit.
It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10266 + 10267.
It is an arithmetic number, because the mean of its divisors is an integer number (10267).
220533 is an apocalyptic number.
It is an amenable number.
20533 is a deficient number, since it is larger than the sum of its proper divisors (1).
20533 is an equidigital number, since it uses as much as digits as its factorization.
20533 is an evil number, because the sum of its binary digits is even.
The product of its (nonzero) digits is 90, while the sum is 13.
The square root of 20533 is about 143.2934052914.
The cubic root of 20533 is about 27.3831960474.
The spelling of 20533 in words is "twenty thousand, five hundred thirty-three".