11663865 has 16 divisors (see below), whose sum is σ = 20736000. Its totient is φ = 6220656.

The previous prime is 11663863. The next prime is 11663893. The reversal of 11663865 is 56836611.

It is a happy number.

11663865 is a `hidden beast` number, since 1 + 16 + 638 + 6 + 5 = 666.

11663865 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 11663865 - 2¹ = 11663863 is a prime.

It is not an unprimeable number, because it can be changed into a prime (11663863) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 43065 + ... + 43334.

It is an arithmetic number, because the mean of its divisors is an integer number (1296000).

Almost surely, 2^11663865 is an apocalyptic number.

11663865 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

11663865 is a deficient number, since it is larger than the sum of its proper divisors (9072135).

11663865 is an equidigital number, since it uses as much as digits as its factorization.

11663865 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 86413 (or 86407 counting only the distinct ones).

The product of its digits is 25920, while the sum is 36.

The square root of 11663865 is about 3415.2401086893. The cubic root of 11663865 is about 226.7849140325.

The spelling of 11663865 in words is "eleven million, six hundred sixty-three thousand, eight hundred sixty-five".