221121131321 has 2 divisors, whose sum is σ = 221121131322. Its totient is φ = 221121131320.

The previous prime is 221121131279. The next prime is 221121131333. The reversal of 221121131321 is 123131121122.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 153146212921 + 67974918400 = 391339^2 + 260720^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-221121131321 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 221121131293 and 221121131302.

It is not a weakly prime, because it can be changed into another prime (221121631321) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110560565660 + 110560565661.

It is an arithmetic number, because the mean of its divisors is an integer number (110560565661).

Almost surely, 2^221121131321 is an apocalyptic number.

It is an amenable number.

221121131321 is a deficient number, since it is larger than the sum of its proper divisors (1).

221121131321 is an equidigital number, since it uses as much as digits as its factorization.

221121131321 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 144, while the sum is 20.

Adding to 221121131321 its reverse (123131121122), we get a palindrome (344252252443).

The spelling of 221121131321 in words is "two hundred twenty-one billion, one hundred twenty-one million, one hundred thirty-one thousand, three hundred twenty-one".