11811865 has 8 divisors (see below), whose sum is σ = 15264648. Its totient is φ = 8722560.

The previous prime is 11811853. The next prime is 11811869. The reversal of 11811865 is 56811811.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 53824 + 11758041 = 232^2 + 3429^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 11811865 - 2¹¹ = 11809817 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (11811869) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 90796 + ... + 90925.

It is an arithmetic number, because the mean of its divisors is an integer number (1908081).

Almost surely, 2^11811865 is an apocalyptic number.

It is an amenable number.

11811865 is a deficient number, since it is larger than the sum of its proper divisors (3452783).

11811865 is a wasteful number, since it uses less digits than its factorization.

11811865 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 181739.

The product of its digits is 1920, while the sum is 31.

The square root of 11811865 is about 3436.8393910685. The cubic root of 11811865 is about 227.7400918990.

The spelling of 11811865 in words is "eleven million, eight hundred eleven thousand, eight hundred sixty-five".