201221100101 has 4 divisors (see below), whose sum is σ = 229966971552. Its totient is φ = 172475228652.

The previous prime is 201221100079. The next prime is 201221100163. The reversal of 201221100101 is 101001122102.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-201221100101 is a prime.

It is a super-2 number, since 2×201221100101² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (201221100191) 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, 14372935715 + ... + 14372935728.

It is an arithmetic number, because the mean of its divisors is an integer number (57491742888).

Almost surely, 2^201221100101 is an apocalyptic number.

It is an amenable number.

201221100101 is a deficient number, since it is larger than the sum of its proper divisors (28745871451).

201221100101 is an equidigital number, since it uses as much as digits as its factorization.

201221100101 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28745871450.

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

Adding to 201221100101 its reverse (101001122102), we get a palindrome (302222222203).

The spelling of 201221100101 in words is "two hundred one billion, two hundred twenty-one million, one hundred thousand, one hundred one".