11573735681 has 4 divisors (see below), whose sum is σ = 11587531200. Its totient is φ = 11559940164.

The previous prime is 11573735669. The next prime is 11573735699. The reversal of 11573735681 is 18653737511.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 18653737511 = 4637 ⋅4022803.

It is a cyclic number.

It is not a de Polignac number, because 11573735681 - 2³⁰ = 10499993857 is a prime.

It is a super-2 number, since 2×11573735681² (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 (11573735611) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6896501 + ... + 6898178.

It is an arithmetic number, because the mean of its divisors is an integer number (2896882800).

Almost surely, 2^11573735681 is an apocalyptic number.

It is an amenable number.

11573735681 is a deficient number, since it is larger than the sum of its proper divisors (13795519).

11573735681 is an equidigital number, since it uses as much as digits as its factorization.

11573735681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13795518.

The product of its digits is 529200, while the sum is 47.

The spelling of 11573735681 in words is "eleven billion, five hundred seventy-three million, seven hundred thirty-five thousand, six hundred eighty-one".