111100221521 has 2 divisors, whose sum is σ = 111100221522. Its totient is φ = 111100221520.

The previous prime is 111100221497. The next prime is 111100221571. The reversal of 111100221521 is 125122001111.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 91116441025 + 19983780496 = 301855^2 + 141364^2 .

It is a cyclic number.

It is not a de Polignac number, because 111100221521 - 2³⁰ = 110026479697 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 111100221521.

It is not a weakly prime, because it can be changed into another prime (111100221571) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 55550110760 + 55550110761.

It is an arithmetic number, because the mean of its divisors is an integer number (55550110761).

Almost surely, 2^111100221521 is an apocalyptic number.

It is an amenable number.

111100221521 is a deficient number, since it is larger than the sum of its proper divisors (1).

111100221521 is an equidigital number, since it uses as much as digits as its factorization.

111100221521 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 40, while the sum is 17.

Adding to 111100221521 its reverse (125122001111), we get a palindrome (236222222632).

The spelling of 111100221521 in words is "one hundred eleven billion, one hundred million, two hundred twenty-one thousand, five hundred twenty-one".