11866947591 has 48 divisors (see below), whose sum is σ = 17312640000. Its totient is φ = 7221726720.

The previous prime is 11866947577. The next prime is 11866947593. The reversal of 11866947591 is 19574966811.

It is a happy number.

It is not a de Polignac number, because 11866947591 - 2⁶ = 11866947527 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (57).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11866947593) 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 47 ways as a sum of consecutive naturals, for example, 9500535 + ... + 9501783.

It is an arithmetic number, because the mean of its divisors is an integer number (360680000).

Almost surely, 2^11866947591 is an apocalyptic number.

11866947591 is a deficient number, since it is larger than the sum of its proper divisors (5445692409).

11866947591 is a wasteful number, since it uses less digits than its factorization.

11866947591 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1604 (or 1585 counting only the distinct ones).

The product of its digits is 3265920, while the sum is 57.

It can be divided in two parts, 1186694 and 7591, that added together give a triangular number (1194285 = T₁₅₄₅).

The spelling of 11866947591 in words is "eleven billion, eight hundred sixty-six million, nine hundred forty-seven thousand, five hundred ninety-one".