11211020221 has 4 divisors (see below), whose sum is σ = 11211232032. Its totient is φ = 11210808412.

The previous prime is 11211020173. The next prime is 11211020257. The reversal of 11211020221 is 12202011211.

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, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 12202011211 = 13 ⋅938616247.

It is a cyclic number.

It is not a de Polignac number, because 11211020221 - 2²¹ = 11208923069 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 (11211020921) 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, 49650 + ... + 157756.

It is an arithmetic number, because the mean of its divisors is an integer number (2802808008).

Almost surely, 2^11211020221 is an apocalyptic number.

It is an amenable number.

11211020221 is a deficient number, since it is larger than the sum of its proper divisors (211811).

11211020221 is a wasteful number, since it uses less digits than its factorization.

11211020221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 211810.

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

Adding to 11211020221 its reverse (12202011211), we get a palindrome (23413031432).

The spelling of 11211020221 in words is "eleven billion, two hundred eleven million, twenty thousand, two hundred twenty-one".