111121212220221 has 16 divisors (see below), whose sum is σ = 172783226000000. Its totient is φ = 63497835553824.

The previous prime is 111121212220211. The next prime is 111121212220231. The reversal of 111121212220221 is 122022212121111.

It is an interprime number because it is at equal distance from previous prime (111121212220211) and next prime (111121212220231).

It is not a de Polignac number, because 111121212220221 - 2⁷ = 111121212220093 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (111121212220211) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 53994757096 + ... + 53994759153.

It is an arithmetic number, because the mean of its divisors is an integer number (10798951625000).

Almost surely, 2^{111121212220221} is an apocalyptic number.

It is an amenable number.

111121212220221 is a deficient number, since it is larger than the sum of its proper divisors (61662013779779).

111121212220221 is an equidigital number, since it uses as much as digits as its factorization.

111121212220221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 107989516273 (or 107989516259 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 21.

Adding to 111121212220221 its reverse (122022212121111), we get a palindrome (233143424341332).

The spelling of 111121212220221 in words is "one hundred eleven trillion, one hundred twenty-one billion, two hundred twelve million, two hundred twenty thousand, two hundred twenty-one".