11866555 has 4 divisors (see below), whose sum is σ = 14239872. Its totient is φ = 9493240.

The previous prime is 11866553. The next prime is 11866567. The reversal of 11866555 is 55566811.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 55566811 = 19 ⋅2924569.

It is not a de Polignac number, because 11866555 - 2¹ = 11866553 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (11866553) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1186651 + ... + 1186660.

It is an arithmetic number, because the mean of its divisors is an integer number (3559968).

Almost surely, 2^11866555 is an apocalyptic number.

11866555 is a deficient number, since it is larger than the sum of its proper divisors (2373317).

11866555 is an equidigital number, since it uses as much as digits as its factorization.

11866555 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2373316.

The product of its digits is 36000, while the sum is 37.

The square root of 11866555 is about 3444.7866407080. The cubic root of 11866555 is about 228.0910365400.

It can be divided in two parts, 11866 and 555, that added together give a palindrome (12421).

The spelling of 11866555 in words is "eleven million, eight hundred sixty-six thousand, five hundred fifty-five".