3121210211221 has 2 divisors, whose sum is σ = 3121210211222. Its totient is φ = 3121210211220.

The previous prime is 3121210211137. The next prime is 3121210211227. The reversal of 3121210211221 is 1221120121213.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 3105243108900 + 15967102321 = 1762170^2 + 126361^2 .

It is a cyclic number.

It is not a de Polignac number, because 3121210211221 - 2¹³ = 3121210203029 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (3121210211227) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1560605105610 + 1560605105611.

It is an arithmetic number, because the mean of its divisors is an integer number (1560605105611).

Almost surely, 2^{3121210211221} is an apocalyptic number.

It is an amenable number.

3121210211221 is a deficient number, since it is larger than the sum of its proper divisors (1).

3121210211221 is an equidigital number, since it uses as much as digits as its factorization.

3121210211221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 96, while the sum is 19.

Adding to 3121210211221 its reverse (1221120121213), we get a palindrome (4342330332434).

The spelling of 3121210211221 in words is "three trillion, one hundred twenty-one billion, two hundred ten million, two hundred eleven thousand, two hundred twenty-one".