201221112121 has 16 divisors (see below), whose sum is σ = 209930206464. Its totient is φ = 192700295424.

The previous prime is 201221112049. The next prime is 201221112163. The reversal of 201221112121 is 121211122102.

It is a cyclic number.

It is not a de Polignac number, because 201221112121 - 2¹³ = 201221103929 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 201221112095 and 201221112104.

It is not an unprimeable number, because it can be changed into a prime (201221112721) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3359185 + ... + 3418561.

It is an arithmetic number, because the mean of its divisors is an integer number (13120637904).

Almost surely, 2^201221112121 is an apocalyptic number.

It is an amenable number.

201221112121 is a deficient number, since it is larger than the sum of its proper divisors (8709094343).

201221112121 is a wasteful number, since it uses less digits than its factorization.

201221112121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 60960.

The product of its (nonzero) digits is 32, while the sum is 16.

Adding to 201221112121 its reverse (121211122102), we get a palindrome (322432234223).

The spelling of 201221112121 in words is "two hundred one billion, two hundred twenty-one million, one hundred twelve thousand, one hundred twenty-one".