3121232221 has 2 divisors, whose sum is σ = 3121232222. Its totient is φ = 3121232220.

The previous prime is 3121232203. The next prime is 3121232287. The reversal of 3121232221 is 1222321213.

3121232221 is digitally balanced in base 2, 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., 2350892196 + 770340025 = 48486^2 + 27755^2 .

It is an emirp because it is prime and its reverse (1222321213) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 3121232221 - 2¹¹ = 3121230173 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (3121232321) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1560616110 + 1560616111.

It is an arithmetic number, because the mean of its divisors is an integer number (1560616111).

Almost surely, 2^3121232221 is an apocalyptic number.

It is an amenable number.

3121232221 is a deficient number, since it is larger than the sum of its proper divisors (1).

3121232221 is an equidigital number, since it uses as much as digits as its factorization.

3121232221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 288, while the sum is 19.

The square root of 3121232221 is about 55867.9892335495. The cubic root of 3121232221 is about 1461.4210566631.

Adding to 3121232221 its reverse (1222321213), we get a palindrome (4343553434).

The spelling of 3121232221 in words is "three billion, one hundred twenty-one million, two hundred thirty-two thousand, two hundred twenty-one".