11665813 has 2 divisors, whose sum is σ = 11665814. Its totient is φ = 11665812.

The previous prime is 11665789. The next prime is 11665817. The reversal of 11665813 is 31856611.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 8305924 + 3359889 = 2882^2 + 1833^2 .

It is an emirp because it is prime and its reverse (31856611) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 11665813 - 2¹⁷ = 11534741 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (11665817) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5832906 + 5832907.

It is an arithmetic number, because the mean of its divisors is an integer number (5832907).

Almost surely, 2^11665813 is an apocalyptic number.

It is an amenable number.

11665813 is a deficient number, since it is larger than the sum of its proper divisors (1).

11665813 is an equidigital number, since it uses as much as digits as its factorization.

11665813 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4320, while the sum is 31.

The square root of 11665813 is about 3415.5252890295. The cubic root of 11665813 is about 226.7975385620.

The spelling of 11665813 in words is "eleven million, six hundred sixty-five thousand, eight hundred thirteen".