201221211001 has 2 divisors, whose sum is σ = 201221211002. Its totient is φ = 201221211000.

The previous prime is 201221210989. The next prime is 201221211011. The reversal of 201221211001 is 100112122102.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 201220427776 + 783225 = 448576^2 + 885^2 .

It is a cyclic number.

It is not a de Polignac number, because 201221211001 - 2²⁵ = 201187656569 is a prime.

It is not a weakly prime, because it can be changed into another prime (201221211011) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 100610605500 + 100610605501.

It is an arithmetic number, because the mean of its divisors is an integer number (100610605501).

Almost surely, 2^201221211001 is an apocalyptic number.

It is an amenable number.

201221211001 is a deficient number, since it is larger than the sum of its proper divisors (1).

201221211001 is an equidigital number, since it uses as much as digits as its factorization.

201221211001 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 201221211001 its reverse (100112122102), we get a palindrome (301333333103).

The spelling of 201221211001 in words is "two hundred one billion, two hundred twenty-one million, two hundred eleven thousand, one".