11543185681 has 2 divisors, whose sum is σ = 11543185682. Its totient is φ = 11543185680.

The previous prime is 11543185679. The next prime is 11543185711. The reversal of 11543185681 is 18658134511.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11505780225 + 37405456 = 107265^2 + 6116^2 .

It is a cyclic number.

It is not a de Polignac number, because 11543185681 - 2¹ = 11543185679 is a prime.

It is a super-2 number, since 2×11543185681² (a number of 21 digits) contains 22 as substring.

Together with 11543185679, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (11543185601) 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 as a sum of consecutive naturals, namely, 5771592840 + 5771592841.

It is an arithmetic number, because the mean of its divisors is an integer number (5771592841).

Almost surely, 2^11543185681 is an apocalyptic number.

It is an amenable number.

11543185681 is a deficient number, since it is larger than the sum of its proper divisors (1).

11543185681 is an equidigital number, since it uses as much as digits as its factorization.

11543185681 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 115200, while the sum is 43.

The spelling of 11543185681 in words is "eleven billion, five hundred forty-three million, one hundred eighty-five thousand, six hundred eighty-one".