1211112221 has 8 divisors (see below), whose sum is σ = 1334835264. Its totient is φ = 1089659520.

The previous prime is 1211112163. The next prime is 1211112229. The reversal of 1211112221 is 1222111121.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1211112221 - 2¹⁸ = 1210850077 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1211112196 and 1211112205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1211112229) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 566465 + ... + 568598.

It is an arithmetic number, because the mean of its divisors is an integer number (166854408).

Almost surely, 2^1211112221 is an apocalyptic number.

1211112221 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1211112221 is a deficient number, since it is larger than the sum of its proper divisors (123723043).

1211112221 is a wasteful number, since it uses less digits than its factorization.

1211112221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1135171.

The product of its digits is 16, while the sum is 14.

The square root of 1211112221 is about 34801.0376425761. The cubic root of 1211112221 is about 1065.9286340761.

Adding to 1211112221 its reverse (1222111121), we get a palindrome (2433223342).

The spelling of 1211112221 in words is "one billion, two hundred eleven million, one hundred twelve thousand, two hundred twenty-one".