11555544566 has 8 divisors (see below), whose sum is σ = 17931017520. Its totient is φ = 5578538728.

The previous prime is 11555544541. The next prime is 11555544613. The reversal of 11555544566 is 66544555511.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-2 number, since 2×11555544566² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 11555544566.

It is a congruent number.

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 3 ways as a sum of consecutive naturals, for example, 99616706 + ... + 99616821.

It is an arithmetic number, because the mean of its divisors is an integer number (2241377190).

Almost surely, 2^11555544566 is an apocalyptic number.

11555544566 is a deficient number, since it is larger than the sum of its proper divisors (6375472954).

11555544566 is a wasteful number, since it uses less digits than its factorization.

11555544566 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 199233558.

The product of its digits is 1800000, while the sum is 47.

It can be divided in two parts, 115555445 and 66, that added together give a palindrome (115555511).

The spelling of 11555544566 in words is "eleven billion, five hundred fifty-five million, five hundred forty-four thousand, five hundred sixty-six".