2153210221 has 2 divisors, whose sum is σ = 2153210222. Its totient is φ = 2153210220.

The previous prime is 2153210203. The next prime is 2153210237. The reversal of 2153210221 is 1220123512.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1533897225 + 619312996 = 39165^2 + 24886^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2153210221 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2153210261) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1076605110 + 1076605111.

It is an arithmetic number, because the mean of its divisors is an integer number (1076605111).

Almost surely, 2^2153210221 is an apocalyptic number.

It is an amenable number.

2153210221 is a deficient number, since it is larger than the sum of its proper divisors (1).

2153210221 is an equidigital number, since it uses as much as digits as its factorization.

2153210221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 240, while the sum is 19.

The square root of 2153210221 is about 46402.6962686437. The cubic root of 2153210221 is about 1291.3049353453.

Adding to 2153210221 its reverse (1220123512), we get a palindrome (3373333733).

The spelling of 2153210221 in words is "two billion, one hundred fifty-three million, two hundred ten thousand, two hundred twenty-one".