111111110521 has 2 divisors, whose sum is σ = 111111110522. Its totient is φ = 111111110520.

The previous prime is 111111110489. The next prime is 111111110587. The reversal of 111111110521 is 125011111111.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 105632150121 + 5478960400 = 325011^2 + 74020^2 .

It is an emirp because it is prime and its reverse (125011111111) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 111111110521 - 2⁵ = 111111110489 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 111111110495 and 111111110504.

It is not a weakly prime, because it can be changed into another prime (111171110521) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 55555555260 + 55555555261.

It is an arithmetic number, because the mean of its divisors is an integer number (55555555261).

Almost surely, 2^111111110521 is an apocalyptic number.

It is an amenable number.

111111110521 is a deficient number, since it is larger than the sum of its proper divisors (1).

111111110521 is an equidigital number, since it uses as much as digits as its factorization.

111111110521 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 10, while the sum is 16.

Adding to 111111110521 its reverse (125011111111), we get a palindrome (236122221632).

The spelling of 111111110521 in words is "one hundred eleven billion, one hundred eleven million, one hundred ten thousand, five hundred twenty-one".