11511709337881 has 9 divisors (see below), whose sum is σ = 12034061282271. Its totient is φ = 11011125592632.

The previous prime is 11511709337873. The next prime is 11511709337897. The reversal of 11511709337881 is 18873390711511.

The square root of 11511709337881 is 3392891.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 5624700006025 + 5887009331856 = 2371645^2 + 2426316^2 .

It is not a de Polignac number, because 11511709337881 - 2³ = 11511709337873 is a prime.

It is a super-2 number, since 2×11511709337881² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (11511709337081) 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 in 8 ways as a sum of consecutive naturals, for example, 77962735 + ... + 78110251.

Almost surely, 2^{11511709337881} is an apocalyptic number.

11511709337881 is the 3392891-st square number.

11511709337881 is the 1696446-th centered octagonal number.

It is an amenable number.

11511709337881 is a deficient number, since it is larger than the sum of its proper divisors (522351944390).

11511709337881 is an frugal number, since it uses more digits than its factorization.

11511709337881 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 295080 (or 147540 counting only the distinct ones).

The product of its (nonzero) digits is 1270080, while the sum is 55.

The spelling of 11511709337881 in words is "eleven trillion, five hundred eleven billion, seven hundred nine million, three hundred thirty-seven thousand, eight hundred eighty-one".