11565811 has 2 divisors, whose sum is σ = 11565812. Its totient is φ = 11565810.

The previous prime is 11565787. The next prime is 11565823. The reversal of 11565811 is 11856511.

It is a strong prime.

It is an emirp because it is prime and its reverse (11856511) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 11565811 - 2¹⁵ = 11533043 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 11565811.

It is not a weakly prime, because it can be changed into another prime (11566811) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5782905 + 5782906.

It is an arithmetic number, because the mean of its divisors is an integer number (5782906).

Almost surely, 2^11565811 is an apocalyptic number.

11565811 is a deficient number, since it is larger than the sum of its proper divisors (1).

11565811 is an equidigital number, since it uses as much as digits as its factorization.

11565811 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1200, while the sum is 28.

The square root of 11565811 is about 3400.8544514578. The cubic root of 11565811 is about 226.1476245929.

The spelling of 11565811 in words is "eleven million, five hundred sixty-five thousand, eight hundred eleven".