111118721 has 6 divisors (see below), whose sum is σ = 129260610. Its totient is φ = 95244576.

The previous prime is 111118717. The next prime is 111118723. The reversal of 111118721 is 127811111.

It can be written as a sum of positive squares in only one way, i.e., 110986225 + 132496 = 10535^2 + 364^2 .

It is not a de Polignac number, because 111118721 - 2² = 111118717 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (111118723) 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 5 ways as a sum of consecutive naturals, for example, 1133816 + ... + 1133913.

It is an arithmetic number, because the mean of its divisors is an integer number (21543435).

Almost surely, 2^111118721 is an apocalyptic number.

It is an amenable number.

111118721 is a deficient number, since it is larger than the sum of its proper divisors (18141889).

111118721 is an equidigital number, since it uses as much as digits as its factorization.

111118721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2267743 (or 2267736 counting only the distinct ones).

The product of its digits is 112, while the sum is 23.

The square root of 111118721 is about 10541.2864964387. The cubic root of 111118721 is about 480.7608318776.

Adding to 111118721 its reverse (127811111), we get a palindrome (238929832).

The spelling of 111118721 in words is "one hundred eleven million, one hundred eighteen thousand, seven hundred twenty-one".