201021111121 has 2 divisors, whose sum is σ = 201021111122. Its totient is φ = 201021111120.

The previous prime is 201021111113. The next prime is 201021111149. The reversal of 201021111121 is 121111120102.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 103642788096 + 97378323025 = 321936^2 + 312055^2 .

It is a cyclic number.

It is not a de Polignac number, because 201021111121 - 2³ = 201021111113 is a prime.

It is not a weakly prime, because it can be changed into another prime (201021114121) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 100510555560 + 100510555561.

It is an arithmetic number, because the mean of its divisors is an integer number (100510555561).

Almost surely, 2^201021111121 is an apocalyptic number.

It is an amenable number.

201021111121 is a deficient number, since it is larger than the sum of its proper divisors (1).

201021111121 is an equidigital number, since it uses as much as digits as its factorization.

201021111121 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8, while the sum is 13.

Adding to 201021111121 its reverse (121111120102), we get a palindrome (322132231223).

The spelling of 201021111121 in words is "two hundred one billion, twenty-one million, one hundred eleven thousand, one hundred twenty-one".