111222220221 has 72 divisors (see below), whose sum is σ = 190586521944. Its totient is φ = 62298512640.

The previous prime is 111222220189. The next prime is 111222220229. The reversal of 111222220221 is 122022222111.

It is a happy number.

111222220221 is a `hidden beast` number, since 1 + 1 + 1 + 222 + 220 + 221 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 1005524100 + 110216696121 = 31710^2 + 331989^2 .

It is not a de Polignac number, because 111222220221 - 2⁵ = 111222220189 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 111222220194 and 111222220203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (111222220229) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 43495875 + ... + 43498431.

It is an arithmetic number, because the mean of its divisors is an integer number (2647035027).

Almost surely, 2^111222220221 is an apocalyptic number.

It is an amenable number.

111222220221 is a deficient number, since it is larger than the sum of its proper divisors (79364301723).

111222220221 is a wasteful number, since it uses less digits than its factorization.

111222220221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4491 (or 4481 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 18.

Adding to 111222220221 its reverse (122022222111), we get a palindrome (233244442332).

The spelling of 111222220221 in words is "one hundred eleven billion, two hundred twenty-two million, two hundred twenty thousand, two hundred twenty-one".