111222721 has 4 divisors (see below), whose sum is σ = 117765252. Its totient is φ = 104680192.

The previous prime is 111222701. The next prime is 111222731. The reversal of 111222721 is 127222111.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 127222111 = 251 ⋅506861.

It can be written as a sum of positive squares in 2 ways, for example, as 72335025 + 38887696 = 8505^2 + 6236^2 .

It is a cyclic number.

It is not a de Polignac number, because 111222721 - 2¹¹ = 111220673 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (111222701) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3271240 + ... + 3271273.

It is an arithmetic number, because the mean of its divisors is an integer number (29441313).

Almost surely, 2^111222721 is an apocalyptic number.

It is an amenable number.

111222721 is a deficient number, since it is larger than the sum of its proper divisors (6542531).

111222721 is an equidigital number, since it uses as much as digits as its factorization.

111222721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6542530.

The product of its digits is 112, while the sum is 19.

The square root of 111222721 is about 10546.2183269644. The cubic root of 111222721 is about 480.9107722162.

Adding to 111222721 its reverse (127222111), we get a palindrome (238444832).

The spelling of 111222721 in words is "one hundred eleven million, two hundred twenty-two thousand, seven hundred twenty-one".