11323131221 has 2 divisors, whose sum is σ = 11323131222. Its totient is φ = 11323131220.

The previous prime is 11323131217. The next prime is 11323131223. The reversal of 11323131221 is 12213132311.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 7244392996 + 4078738225 = 85114^2 + 63865^2 .

It is an emirp because it is prime and its reverse (12213132311) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 11323131221 - 2² = 11323131217 is a prime.

Together with 11323131223, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 11323131193 and 11323131202.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (11323131223) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5661565610 + 5661565611.

It is an arithmetic number, because the mean of its divisors is an integer number (5661565611).

Almost surely, 2^11323131221 is an apocalyptic number.

It is an amenable number.

11323131221 is a deficient number, since it is larger than the sum of its proper divisors (1).

11323131221 is an equidigital number, since it uses as much as digits as its factorization.

11323131221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 216, while the sum is 20.

Adding to 11323131221 its reverse (12213132311), we get a palindrome (23536263532).

The spelling of 11323131221 in words is "eleven billion, three hundred twenty-three million, one hundred thirty-one thousand, two hundred twenty-one".