11211210221 has 4 divisors (see below), whose sum is σ = 11217834012. Its totient is φ = 11204586432.

The previous prime is 11211210209. The next prime is 11211210259. The reversal of 11211210221 is 12201211211.

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 5588310025 + 5622900196 = 74755^2 + 74986^2 .

It is a cyclic number.

It is not a de Polignac number, because 11211210221 - 2¹⁴ = 11211193837 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 11211210196 and 11211210205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11211210721) 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, 3309356 + ... + 3312741.

It is an arithmetic number, because the mean of its divisors is an integer number (2804458503).

Almost surely, 2^11211210221 is an apocalyptic number.

It is an amenable number.

11211210221 is a deficient number, since it is larger than the sum of its proper divisors (6623791).

11211210221 is an equidigital number, since it uses as much as digits as its factorization.

11211210221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6623790.

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

Adding to 11211210221 its reverse (12201211211), we get a palindrome (23412421432).

The spelling of 11211210221 in words is "eleven billion, two hundred eleven million, two hundred ten thousand, two hundred twenty-one".