11643343865 has 4 divisors (see below), whose sum is σ = 13972012644. Its totient is φ = 9314675088.

The previous prime is 11643343861. The next prime is 11643343883. The reversal of 11643343865 is 56834334611.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 56834334611 = 19 ⋅2991280769.

It can be written as a sum of positive squares in 2 ways, for example, as 3843628009 + 7799715856 = 61997^2 + 88316^2 .

It is a cyclic number.

It is not a de Polignac number, because 11643343865 - 2² = 11643343861 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (11643343861) 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, 1164334382 + ... + 1164334391.

It is an arithmetic number, because the mean of its divisors is an integer number (3493003161).

Almost surely, 2^11643343865 is an apocalyptic number.

It is an amenable number.

11643343865 is a deficient number, since it is larger than the sum of its proper divisors (2328668779).

11643343865 is an equidigital number, since it uses as much as digits as its factorization.

11643343865 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2328668778.

The product of its digits is 622080, while the sum is 44.

The spelling of 11643343865 in words is "eleven billion, six hundred forty-three million, three hundred forty-three thousand, eight hundred sixty-five".