11565563431361 has 4 divisors (see below), whose sum is σ = 11834530022832. Its totient is φ = 11296596839892.

The previous prime is 11565563431337. The next prime is 11565563431427. The reversal of 11565563431361 is 16313436556511.

It is a happy number.

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.

It is a cyclic number.

It is not a de Polignac number, because 11565563431361 - 2⁴² = 7167516920257 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (11565563431321) 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, 134483295671 + ... + 134483295756.

It is an arithmetic number, because the mean of its divisors is an integer number (2958632505708).

Almost surely, 2^{11565563431361} is an apocalyptic number.

It is an amenable number.

11565563431361 is a deficient number, since it is larger than the sum of its proper divisors (268966591471).

11565563431361 is an equidigital number, since it uses as much as digits as its factorization.

11565563431361 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 268966591470.

The product of its digits is 2916000, while the sum is 50.

Adding to 11565563431361 its reverse (16313436556511), we get a palindrome (27878999987872).

The spelling of 11565563431361 in words is "eleven trillion, five hundred sixty-five billion, five hundred sixty-three million, four hundred thirty-one thousand, three hundred sixty-one".