201121011111221 has 2 divisors, whose sum is σ = 201121011111222. Its totient is φ = 201121011111220.

The previous prime is 201121011111217. The next prime is 201121011111239. The reversal of 201121011111221 is 122111110121102.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 122669779258321 + 78451231852900 = 11075639^2 + 8857270^2 .

It is a cyclic number.

It is not a de Polignac number, because 201121011111221 - 2² = 201121011111217 is a prime.

It is a super-2 number, since 2×201121011111221² (a number of 29 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 201121011111221.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (201121011111421) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 100560505555610 + 100560505555611.

It is an arithmetic number, because the mean of its divisors is an integer number (100560505555611).

Almost surely, 2^{201121011111221} is an apocalyptic number.

It is an amenable number.

201121011111221 is a deficient number, since it is larger than the sum of its proper divisors (1).

201121011111221 is an equidigital number, since it uses as much as digits as its factorization.

201121011111221 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 16, while the sum is 17.

Adding to 201121011111221 its reverse (122111110121102), we get a palindrome (323232121232323).

The spelling of 201121011111221 in words is "two hundred one trillion, one hundred twenty-one billion, eleven million, one hundred eleven thousand, two hundred twenty-one".