11811711761 has 4 divisors (see below), whose sum is σ = 12130947252. Its totient is φ = 11492476272.

The previous prime is 11811711757. The next prime is 11811711773. The reversal of 11811711761 is 16711711811.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 7811908225 + 3999803536 = 88385^2 + 63244^2 .

It is a cyclic number.

It is not a de Polignac number, because 11811711761 - 2² = 11811711757 is a prime.

It is a super-2 number, since 2×11811711761² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (11811711661) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 159617690 + ... + 159617763.

It is an arithmetic number, because the mean of its divisors is an integer number (3032736813).

Almost surely, 2^11811711761 is an apocalyptic number.

It is an amenable number.

11811711761 is a deficient number, since it is larger than the sum of its proper divisors (319235491).

11811711761 is an equidigital number, since it uses as much as digits as its factorization.

11811711761 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 319235490.

The product of its digits is 2352, while the sum is 35.

The spelling of 11811711761 in words is "eleven billion, eight hundred eleven million, seven hundred eleven thousand, seven hundred sixty-one".