111211112221 has 24 divisors (see below), whose sum is σ = 123913200600. Its totient is φ = 99724944000.

The previous prime is 111211112213. The next prime is 111211112239. The reversal of 111211112221 is 122211112111.

It can be written as a sum of positive squares in 4 ways, for example, as 29408820100 + 81802292121 = 171490^2 + 286011^2 .

It is not a de Polignac number, because 111211112221 - 2³ = 111211112213 is a prime.

It is a super-2 number, since 2×111211112221² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 111211112195 and 111211112204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (111211112281) 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, 3270535 + ... + 3304363.

It is an arithmetic number, because the mean of its divisors is an integer number (5163050025).

Almost surely, 2^111211112221 is an apocalyptic number.

111211112221 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

111211112221 is a deficient number, since it is larger than the sum of its proper divisors (12702088379).

111211112221 is a wasteful number, since it uses less digits than its factorization.

111211112221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34221 (or 34210 counting only the distinct ones).

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

Adding to 111211112221 its reverse (122211112111), we get a palindrome (233422224332).

The spelling of 111211112221 in words is "one hundred eleven billion, two hundred eleven million, one hundred twelve thousand, two hundred twenty-one".