11211221211211 has 4 divisors (see below), whose sum is σ = 12812824241392. Its totient is φ = 9609618181032.

The previous prime is 11211221211209. The next prime is 11211221211221. The reversal of 11211221211211 is 11211212211211.

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

It is a cyclic number.

It is not a de Polignac number, because 11211221211211 - 2¹ = 11211221211209 is a prime.

It is not an unprimeable number, because it can be changed into a prime (11211221211221) 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, 800801515080 + ... + 800801515093.

It is an arithmetic number, because the mean of its divisors is an integer number (3203206060348).

Almost surely, 2^{11211221211211} is an apocalyptic number.

11211221211211 is a deficient number, since it is larger than the sum of its proper divisors (1601603030181).

11211221211211 is an equidigital number, since it uses as much as digits as its factorization.

11211221211211 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1601603030180.

The product of its digits is 32, while the sum is 19.

Adding to 11211221211211 its reverse (11211212211211), we get a palindrome (22422433422422).

Subtracting from 11211221211211 its reverse (11211212211211), we obtain a square (9000000 = 3000²).

The spelling of 11211221211211 in words is "eleven trillion, two hundred eleven billion, two hundred twenty-one million, two hundred eleven thousand, two hundred eleven".