21111222113 has 2 divisors, whose sum is σ = 21111222114. Its totient is φ = 21111222112.

The previous prime is 21111222091. The next prime is 21111222151. The reversal of 21111222113 is 31122211112.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21109765264 + 1456849 = 145292^2 + 1207^2 .

It is a cyclic number.

It is not a de Polignac number, because 21111222113 - 2⁶ = 21111222049 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21111222091 and 21111222100.

It is not a weakly prime, because it can be changed into another prime (21111222163) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10555611056 + 10555611057.

It is an arithmetic number, because the mean of its divisors is an integer number (10555611057).

Almost surely, 2^21111222113 is an apocalyptic number.

It is an amenable number.

21111222113 is a deficient number, since it is larger than the sum of its proper divisors (1).

21111222113 is an equidigital number, since it uses as much as digits as its factorization.

21111222113 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 48, while the sum is 17.

Adding to 21111222113 its reverse (31122211112), we get a palindrome (52233433225).

The spelling of 21111222113 in words is "twenty-one billion, one hundred eleven million, two hundred twenty-two thousand, one hundred thirteen".