221131111 has 2 divisors, whose sum is σ = 221131112. Its totient is φ = 221131110.

The previous prime is 221131109. The next prime is 221131147. The reversal of 221131111 is 111131122.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 221131111 - 2¹ = 221131109 is a prime.

Together with 221131109, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 221131091 and 221131100.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221131171) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110565555 + 110565556.

It is an arithmetic number, because the mean of its divisors is an integer number (110565556).

Almost surely, 2^221131111 is an apocalyptic number.

221131111 is a deficient number, since it is larger than the sum of its proper divisors (1).

221131111 is an equidigital number, since it uses as much as digits as its factorization.

221131111 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 12, while the sum is 13.

The square root of 221131111 is about 14870.4778336138. The cubic root of 221131111 is about 604.7138970077.

Adding to 221131111 its reverse (111131122), we get a palindrome (332262233).

The spelling of 221131111 in words is "two hundred twenty-one million, one hundred thirty-one thousand, one hundred eleven".