111220212121 has 2 divisors, whose sum is σ = 111220212122. Its totient is φ = 111220212120.

The previous prime is 111220212109. The next prime is 111220212193. The reversal of 111220212121 is 121212022111.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 98147491225 + 13072720896 = 313285^2 + 114336^2 .

It is a cyclic number.

It is not a de Polignac number, because 111220212121 - 2¹⁵ = 111220179353 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 111220212095 and 111220212104.

It is not a weakly prime, because it can be changed into another prime (111220212221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 55610106060 + 55610106061.

It is an arithmetic number, because the mean of its divisors is an integer number (55610106061).

Almost surely, 2^111220212121 is an apocalyptic number.

It is an amenable number.

111220212121 is a deficient number, since it is larger than the sum of its proper divisors (1).

111220212121 is an equidigital number, since it uses as much as digits as its factorization.

111220212121 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 32, while the sum is 16.

Adding to 111220212121 its reverse (121212022111), we get a palindrome (232432234232).

The spelling of 111220212121 in words is "one hundred eleven billion, two hundred twenty million, two hundred twelve thousand, one hundred twenty-one".