11131222221 has 96 divisors (see below), whose sum is σ = 19361721600. Its totient is φ = 6028646400.

The previous prime is 11131222187. The next prime is 11131222229. The reversal of 11131222221 is 12222213111.

11131222221 is a `hidden beast` number, since 111 + 312 + 22 + 221 = 666.

It is not a de Polignac number, because 11131222221 - 2²² = 11127027917 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 11131222194 and 11131222203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11131222229) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 33030165 + ... + 33030501.

It is an arithmetic number, because the mean of its divisors is an integer number (201684600).

Almost surely, 2^11131222221 is an apocalyptic number.

It is an amenable number.

11131222221 is a deficient number, since it is larger than the sum of its proper divisors (8230499379).

11131222221 is a wasteful number, since it uses less digits than its factorization.

11131222221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 659 (or 656 counting only the distinct ones).

The product of its digits is 96, while the sum is 18.

Adding to 11131222221 its reverse (12222213111), we get a palindrome (23353435332).

The spelling of 11131222221 in words is "eleven billion, one hundred thirty-one million, two hundred twenty-two thousand, two hundred twenty-one".