201221120101 has 4 divisors (see below), whose sum is σ = 203001838092. Its totient is φ = 199440402112.

The previous prime is 201221120099. The next prime is 201221120153. The reversal of 201221120101 is 101021122102.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 101021122102 = 2 ⋅50510561051.

It can be written as a sum of positive squares in 2 ways, for example, as 21097272001 + 180123848100 = 145249^2 + 424410^2 .

It is a cyclic number.

It is not a de Polignac number, because 201221120101 - 2¹ = 201221120099 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (201221120201) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 890358826 + ... + 890359051.

It is an arithmetic number, because the mean of its divisors is an integer number (50750459523).

Almost surely, 2^201221120101 is an apocalyptic number.

It is an amenable number.

201221120101 is a deficient number, since it is larger than the sum of its proper divisors (1780717991).

201221120101 is a wasteful number, since it uses less digits than its factorization.

201221120101 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1780717990.

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

Adding to 201221120101 its reverse (101021122102), we get a palindrome (302242242203).

The spelling of 201221120101 in words is "two hundred one billion, two hundred twenty-one million, one hundred twenty thousand, one hundred one".