11565505243 has 2 divisors, whose sum is σ = 11565505244. Its totient is φ = 11565505242.

The previous prime is 11565505241. The next prime is 11565505249. The reversal of 11565505243 is 34250556511.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 11565505243 - 2¹ = 11565505241 is a prime.

Together with 11565505241, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (11565505241) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5782752621 + 5782752622.

It is an arithmetic number, because the mean of its divisors is an integer number (5782752622).

Almost surely, 2^11565505243 is an apocalyptic number.

11565505243 is a deficient number, since it is larger than the sum of its proper divisors (1).

11565505243 is an equidigital number, since it uses as much as digits as its factorization.

11565505243 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 90000, while the sum is 37.

The spelling of 11565505243 in words is "eleven billion, five hundred sixty-five million, five hundred five thousand, two hundred forty-three".