201021111221 has 4 divisors (see below), whose sum is σ = 229738412832. Its totient is φ = 172303809612.

The previous prime is 201021111149. The next prime is 201021111223. The reversal of 201021111221 is 122111120102.

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 not a de Polignac number, because 201021111221 - 2¹⁰ = 201021110197 is a prime.

It is a super-2 number, since 2×201021111221² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 201021111196 and 201021111205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (201021111223) 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, 14358650795 + ... + 14358650808.

It is an arithmetic number, because the mean of its divisors is an integer number (57434603208).

Almost surely, 2^201021111221 is an apocalyptic number.

It is an amenable number.

201021111221 is a deficient number, since it is larger than the sum of its proper divisors (28717301611).

201021111221 is an equidigital number, since it uses as much as digits as its factorization.

201021111221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28717301610.

The product of its (nonzero) digits is 16, while the sum is 14.

Adding to 201021111221 its reverse (122111120102), we get a palindrome (323132231323).

The spelling of 201021111221 in words is "two hundred one billion, twenty-one million, one hundred eleven thousand, two hundred twenty-one".