11231221211 has 4 divisors (see below), whose sum is σ = 12835681392. Its totient is φ = 9626761032.

The previous prime is 11231221171. The next prime is 11231221219. The reversal of 11231221211 is 11212213211.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 11212213211 = 439 ⋅25540349.

It is not a de Polignac number, because 11231221211 - 2¹⁴ = 11231204827 is a prime.

It is a super-2 number, since 2×11231221211² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 11231221211.

It is not an unprimeable number, because it can be changed into a prime (11231221219) 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, 802230080 + ... + 802230093.

It is an arithmetic number, because the mean of its divisors is an integer number (3208920348).

Almost surely, 2^11231221211 is an apocalyptic number.

11231221211 is a deficient number, since it is larger than the sum of its proper divisors (1604460181).

11231221211 is an equidigital number, since it uses as much as digits as its factorization.

11231221211 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1604460180.

The product of its digits is 48, while the sum is 17.

Adding to 11231221211 its reverse (11212213211), we get a palindrome (22443434422).

The spelling of 11231221211 in words is "eleven billion, two hundred thirty-one million, two hundred twenty-one thousand, two hundred eleven".