11131111221 has 16 divisors (see below), whose sum is σ = 15625459200. Its totient is φ = 7028894448.

The previous prime is 11131111207. The next prime is 11131111249. The reversal of 11131111221 is 12211113111.

It is not a de Polignac number, because 11131111221 - 2⁶ = 11131111157 is a prime.

It is a super-2 number, since 2×11131111221² (a number of 21 digits) contains 22 as substring.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 11131111221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11131111421) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 372000 + ... + 400806.

It is an arithmetic number, because the mean of its divisors is an integer number (976591200).

Almost surely, 2^11131111221 is an apocalyptic number.

It is an amenable number.

11131111221 is a deficient number, since it is larger than the sum of its proper divisors (4494347979).

11131111221 is a wasteful number, since it uses less digits than its factorization.

11131111221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35608.

The product of its digits is 12, while the sum is 15.

Adding to 11131111221 its reverse (12211113111), we get a palindrome (23342224332).

The spelling of 11131111221 in words is "eleven billion, one hundred thirty-one million, one hundred eleven thousand, two hundred twenty-one".