5205210221 has 2 divisors, whose sum is σ = 5205210222. Its totient is φ = 5205210220.

The previous prime is 5205210211. The next prime is 5205210251. The reversal of 5205210221 is 1220125025.

It is a happy number.

5205210221 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., 2618368900 + 2586841321 = 51170^2 + 50861^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-5205210221 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 5205210193 and 5205210202.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (5205210211) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2602605110 + 2602605111.

It is an arithmetic number, because the mean of its divisors is an integer number (2602605111).

Almost surely, 2^5205210221 is an apocalyptic number.

It is an amenable number.

5205210221 is a deficient number, since it is larger than the sum of its proper divisors (1).

5205210221 is an equidigital number, since it uses as much as digits as its factorization.

5205210221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 400, while the sum is 20.

The square root of 5205210221 is about 72147.1428471010. The cubic root of 5205210221 is about 1733.0566453775.

Adding to 5205210221 its reverse (1220125025), we get a palindrome (6425335246).

The spelling of 5205210221 in words is "five billion, two hundred five million, two hundred ten thousand, two hundred twenty-one".