11220131221 has 6 divisors (see below), whose sum is σ = 12149609730. Its totient is φ = 10357044048.

The previous prime is 11220131213. The next prime is 11220131249. The reversal of 11220131221 is 12213102211.

It can be written as a sum of positive squares in 3 ways, for example, as 468722500 + 10751408721 = 21650^2 + 103689^2 .

It is not a de Polignac number, because 11220131221 - 2³ = 11220131213 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 11220131195 and 11220131204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11220131821) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 33195486 + ... + 33195823.

It is an arithmetic number, because the mean of its divisors is an integer number (2024934955).

Almost surely, 2^11220131221 is an apocalyptic number.

It is an amenable number.

11220131221 is a deficient number, since it is larger than the sum of its proper divisors (929478509).

11220131221 is an equidigital number, since it uses as much as digits as its factorization.

11220131221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 66391335 (or 66391322 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 16.

Adding to 11220131221 its reverse (12213102211), we get a palindrome (23433233432).

The spelling of 11220131221 in words is "eleven billion, two hundred twenty million, one hundred thirty-one thousand, two hundred twenty-one".