111211121221 has 8 divisors (see below), whose sum is σ = 115051044600. Its totient is φ = 107371535040.

The previous prime is 111211121209. The next prime is 111211121257. The reversal of 111211121221 is 122121112111.

It can be written as a sum of positive squares in 4 ways, for example, as 102232321 + 111108888900 = 10111^2 + 333330^2 .

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 111211121221 - 2²⁷ = 111076903493 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 111211121195 and 111211121204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (111211121821) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 715431 + ... + 856891.

It is an arithmetic number, because the mean of its divisors is an integer number (14381380575).

Almost surely, 2^111211121221 is an apocalyptic number.

It is an amenable number.

111211121221 is a deficient number, since it is larger than the sum of its proper divisors (3839923379).

111211121221 is a wasteful number, since it uses less digits than its factorization.

111211121221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 168599.

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

Adding to 111211121221 its reverse (122121112111), we get a palindrome (233332233332).

The spelling of 111211121221 in words is "one hundred eleven billion, two hundred eleven million, one hundred twenty-one thousand, two hundred twenty-one".