111212201221 has 6 divisors (see below), whose sum is σ = 122241510566. Its totient is φ = 101102001000.

The previous prime is 111212201197. The next prime is 111212201273. The reversal of 111212201221 is 122102212111.

It can be written as a sum of positive squares in only one way, i.e., 106201684996 + 5010516225 = 325886^2 + 70785^2 .

It is not a de Polignac number, because 111212201221 - 2³³ = 102622266629 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 111212201195 and 111212201204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (111212201291) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 459554430 + ... + 459554671.

Almost surely, 2^111212201221 is an apocalyptic number.

111212201221 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

111212201221 is a deficient number, since it is larger than the sum of its proper divisors (11029309345).

111212201221 is an equidigital number, since it uses as much as digits as its factorization.

111212201221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 919109123 (or 919109112 counting only the distinct ones).

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

Adding to 111212201221 its reverse (122102212111), we get a palindrome (233314413332).

The spelling of 111212201221 in words is "one hundred eleven billion, two hundred twelve million, two hundred one thousand, two hundred twenty-one".