1211112112221 has 24 divisors (see below), whose sum is σ = 1908520469856. Its totient is φ = 733968347040.

The previous prime is 1211112112219. The next prime is 1211112112253. The reversal of 1211112112221 is 1222112111121.

It is a happy number.

1211112112221 is a `hidden beast` number, since 121 + 111 + 211 + 2 + 221 = 666.

It is not a de Polignac number, because 1211112112221 - 2¹ = 1211112112219 is a prime.

It is a super-3 number, since 3×1211112112221³ (a number of 37 digits) contains 333 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 1211112112194 and 1211112112203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1211112112121) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1605651 + ... + 2236143.

It is an arithmetic number, because the mean of its divisors is an integer number (79521686244).

Almost surely, 2^{1211112112221} is an apocalyptic number.

1211112112221 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1211112112221 is a deficient number, since it is larger than the sum of its proper divisors (697408357635).

1211112112221 is a wasteful number, since it uses less digits than its factorization.

1211112112221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 649913 (or 649910 counting only the distinct ones).

The product of its digits is 32, while the sum is 18.

Adding to 1211112112221 its reverse (1222112111121), we get a palindrome (2433224223342).

The spelling of 1211112112221 in words is "one trillion, two hundred eleven billion, one hundred twelve million, one hundred twelve thousand, two hundred twenty-one".