5221721 has 2 divisors, whose sum is σ = 5221722. Its totient is φ = 5221720.

The previous prime is 5221717. The next prime is 5221729. The reversal of 5221721 is 1271225.

5221721 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 4243600 + 978121 = 2060^2 + 989^2 .

It is a cyclic number.

It is not a de Polignac number, because 5221721 - 2² = 5221717 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 5221693 and 5221702.

It is not a weakly prime, because it can be changed into another prime (5221729) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2610860 + 2610861.

It is an arithmetic number, because the mean of its divisors is an integer number (2610861).

Almost surely, 2^5221721 is an apocalyptic number.

It is an amenable number.

5221721 is a deficient number, since it is larger than the sum of its proper divisors (1).

5221721 is an equidigital number, since it uses as much as digits as its factorization.

5221721 is an evil number, because the sum of its binary digits is even.

The product of its digits is 280, while the sum is 20.

The square root of 5221721 is about 2285.1085313394. The cubic root of 5221721 is about 173.4887113496.

Adding to 5221721 its reverse (1271225), we get a palindrome (6492946).

The spelling of 5221721 in words is "five million, two hundred twenty-one thousand, seven hundred twenty-one".