11771566866 has 64 divisors (see below), whose sum is σ = 26916729600. Its totient is φ = 3859442640.

The previous prime is 11771566811. The next prime is 11771566879. The reversal of 11771566866 is 66866517711.

11771566866 is a `hidden beast` number, since 1 + 1 + 7 + 71 + 566 + 8 + 6 + 6 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 244755 + ... + 288873.

It is an arithmetic number, because the mean of its divisors is an integer number (420573900).

Almost surely, 2^11771566866 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 11771566866, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (13458364800).

11771566866 is an abundant number, since it is smaller than the sum of its proper divisors (15145162734).

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

11771566866 is an frugal number, since it uses more digits than its factorization.

11771566866 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 44203 (or 44185 counting only the distinct ones).

The product of its digits is 2540160, while the sum is 54.

The spelling of 11771566866 in words is "eleven billion, seven hundred seventy-one million, five hundred sixty-six thousand, eight hundred sixty-six".