111211211020221 has 24 divisors (see below), whose sum is σ = 172995661716696. Its totient is φ = 68437492444800.

The previous prime is 111211211020181. The next prime is 111211211020313. The reversal of 111211211020221 is 122020112112111.

It is a happy number.

111211211020221 is a `hidden beast` number, since 1 + 1 + 1 + 211 + 211 + 0 + 20 + 221 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 5014352525625 + 106196858494596 = 2239275^2 + 10305186^2 .

It is not a de Polignac number, because 111211211020221 - 2⁹ = 111211211019709 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 111211211020194 and 111211211020203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (111211211025221) 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, 55848511 + ... + 57805523.

It is an arithmetic number, because the mean of its divisors is an integer number (7208152571529).

Almost surely, 2^{111211211020221} is an apocalyptic number.

It is an amenable number.

111211211020221 is a deficient number, since it is larger than the sum of its proper divisors (61784450696475).

111211211020221 is a wasteful number, since it uses less digits than its factorization.

111211211020221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2442733 (or 2442730 counting only the distinct ones).

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

Adding to 111211211020221 its reverse (122020112112111), we get a palindrome (233231323132332).

The spelling of 111211211020221 in words is "one hundred eleven trillion, two hundred eleven billion, two hundred eleven million, twenty thousand, two hundred twenty-one".