11971566 has 24 divisors (see below), whose sum is σ = 26141544. Its totient is φ = 3959280.

The previous prime is 11971541. The next prime is 11971567. The reversal of 11971566 is 66517911.

It is a happy number.

11971566 is a `hidden beast` number, since 1 + 1 + 97 + 1 + 566 = 666.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 11971566.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11971567) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 181 + ... + 4896.

It is an arithmetic number, because the mean of its divisors is an integer number (1089231).

Almost surely, 2^11971566 is an apocalyptic number.

11971566 is an abundant number, since it is smaller than the sum of its proper divisors (14169978).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

11971566 is a wasteful number, since it uses less digits than its factorization.

11971566 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5216 (or 5213 counting only the distinct ones).

The product of its digits is 11340, while the sum is 36.

The square root of 11971566 is about 3459.9950867017. The cubic root of 11971566 is about 228.7618788062.

The spelling of 11971566 in words is "eleven million, nine hundred seventy-one thousand, five hundred sixty-six".