221212212113 has 2 divisors, whose sum is σ = 221212212114. Its totient is φ = 221212212112.

The previous prime is 221212212103. The next prime is 221212212121. The reversal of 221212212113 is 311212212122.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 171887355649 + 49324856464 = 414593^2 + 222092^2 .

It is a cyclic number.

It is not a de Polignac number, because 221212212113 - 2¹⁸ = 221211949969 is a prime.

It is not a weakly prime, because it can be changed into another prime (221212212103) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110606106056 + 110606106057.

It is an arithmetic number, because the mean of its divisors is an integer number (110606106057).

Almost surely, 2^221212212113 is an apocalyptic number.

It is an amenable number.

221212212113 is a deficient number, since it is larger than the sum of its proper divisors (1).

221212212113 is an equidigital number, since it uses as much as digits as its factorization.

221212212113 is an evil number, because the sum of its binary digits is even.

The product of its digits is 192, while the sum is 20.

Adding to 221212212113 its reverse (311212212122), we get a palindrome (532424424235).

Subtracting 221212212113 from its reverse (311212212122), we obtain a palindrome (90000000009).

The spelling of 221212212113 in words is "two hundred twenty-one billion, two hundred twelve million, two hundred twelve thousand, one hundred thirteen".