111211211212221 has 8 divisors (see below), whose sum is σ = 150494773381984. Its totient is φ = 73034228258640.

The previous prime is 111211211212141. The next prime is 111211211212247. The reversal of 111211211212221 is 122212112112111.

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

It is not a de Polignac number, because 111211211212221 - 2¹⁰ = 111211211211197 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (111211219212221) 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, 276644803810 + ... + 276644804211.

It is an arithmetic number, because the mean of its divisors is an integer number (18811846672748).

Almost surely, 2^{111211211212221} is an apocalyptic number.

It is an amenable number.

111211211212221 is a deficient number, since it is larger than the sum of its proper divisors (39283562169763).

111211211212221 is an equidigital number, since it uses as much as digits as its factorization.

111211211212221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 553289608091.

The product of its digits is 64, while the sum is 21.

Adding to 111211211212221 its reverse (122212112112111), we get a palindrome (233423323324332).

The spelling of 111211211212221 in words is "one hundred eleven trillion, two hundred eleven billion, two hundred eleven million, two hundred twelve thousand, two hundred twenty-one".