11717128081 has 2 divisors, whose sum is σ = 11717128082. Its totient is φ = 11717128080.

The previous prime is 11717128067. The next prime is 11717128097. The reversal of 11717128081 is 18082171711.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11712650625 + 4477456 = 108225^2 + 2116^2 .

It is an emirp because it is prime and its reverse (18082171711) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 11717128081 - 2⁷ = 11717127953 is a prime.

It is a super-2 number, since 2×11717128081² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 11717128081.

It is not a weakly prime, because it can be changed into another prime (11717128021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5858564040 + 5858564041.

It is an arithmetic number, because the mean of its divisors is an integer number (5858564041).

Almost surely, 2^11717128081 is an apocalyptic number.

It is an amenable number.

11717128081 is a deficient number, since it is larger than the sum of its proper divisors (1).

11717128081 is an equidigital number, since it uses as much as digits as its factorization.

11717128081 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6272, while the sum is 37.

Adding to 11717128081 its reverse (18082171711), we get a palindrome (29799299792).

The spelling of 11717128081 in words is "eleven billion, seven hundred seventeen million, one hundred twenty-eight thousand, eighty-one".