50821 has 2 divisors, whose sum is σ = 50822.
Its totient is φ = 50820.
The previous prime is 50789. The next prime is 50833. The reversal of 50821 is 12805.
Subtracting from 50821 its sum of digits (16), we obtain a palindrome (50805).
It can be divided in two parts, 508 and 21, that added together give a square (529 = 232).
It is a happy number.
50821 is nontrivially palindromic in base 14.
It is a strong prime.
It can be written as a sum of positive squares in only one way, i.e., 50625 + 196 = 225^2 + 14^2
It is a cyclic number.
It is not a de Polignac number, because 50821 - 25 = 50789 is a prime.
It is a junction number, because it is equal to n+sod(n) for n = 50795 and 50804.
It is a congruent number.
It is not a weakly prime, because it can be changed into another prime (50891) by changing a digit.
It is a pernicious number, because its binary representation contains a prime number (7) of ones.
It is a good prime.
It is a polite number, since it can be written as a sum of consecutive naturals, namely, 25410 + 25411.
It is an arithmetic number, because the mean of its divisors is an integer number (25411).
250821 is an apocalyptic number.
50821 is the 121-st centered heptagonal number.
It is an amenable number.
50821 is a deficient number, since it is larger than the sum of its proper divisors (1).
50821 is an equidigital number, since it uses as much as digits as its factorization.
50821 is an odious number, because the sum of its binary digits is odd.
The product of its (nonzero) digits is 80, while the sum is 16.
The square root of 50821 is about 225.4351347949.
The cubic root of 50821 is about 37.0408606299.
The spelling of 50821 in words is "fifty thousand, eight hundred twenty-one".