201221001101 has 4 divisors (see below), whose sum is σ = 201409235100. Its totient is φ = 201032767104.

The previous prime is 201221001083. The next prime is 201221001131. The reversal of 201221001101 is 101100122102.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 55946440900 + 145274560201 = 236530^2 + 381149^2 .

It is a cyclic number.

It is not a de Polignac number, because 201221001101 - 2¹⁰ = 201221000077 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (201221001131) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 94115396 + ... + 94117533.

It is an arithmetic number, because the mean of its divisors is an integer number (50352308775).

Almost surely, 2^201221001101 is an apocalyptic number.

It is an amenable number.

201221001101 is a deficient number, since it is larger than the sum of its proper divisors (188233999).

201221001101 is a wasteful number, since it uses less digits than its factorization.

201221001101 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 188233998.

The product of its (nonzero) digits is 8, while the sum is 11.

Adding to 201221001101 its reverse (101100122102), we get a palindrome (302321123203).

The spelling of 201221001101 in words is "two hundred one billion, two hundred twenty-one million, one thousand, one hundred one".