1111212211221 has 128 divisors (see below), whose sum is σ = 1966947840000. Its totient is φ = 619426652544.

The previous prime is 1111212211181. The next prime is 1111212211289. The reversal of 1111212211221 is 1221122121111.

It is a happy number.

1111212211221 is a `hidden beast` number, since 11 + 11 + 212 + 211 + 221 = 666.

It is a de Polignac number, because none of the positive numbers 2^k-1111212211221 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1111212211194 and 1111212211203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1111212211121) by changing a digit.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 475078870 + ... + 475081208.

It is an arithmetic number, because the mean of its divisors is an integer number (15366780000).

Almost surely, 2^{1111212211221} is an apocalyptic number.

It is an amenable number.

1111212211221 is a deficient number, since it is larger than the sum of its proper divisors (855735628779).

1111212211221 is a wasteful number, since it uses less digits than its factorization.

1111212211221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3605 (or 3585 counting only the distinct ones).

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

Adding to 1111212211221 its reverse (1221122121111), we get a palindrome (2332334332332).

The spelling of 1111212211221 in words is "one trillion, one hundred eleven billion, two hundred twelve million, two hundred eleven thousand, two hundred twenty-one".