15505616666 has 32 divisors (see below), whose sum is σ = 24959233728. Its totient is φ = 7198846720.

The previous prime is 15505616641. The next prime is 15505616713. The reversal of 15505616666 is 66661650551.

It is a self number, because there is not a number n which added to its sum of digits gives 15505616666.

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 15 ways as a sum of consecutive naturals, for example, 760481 + ... + 780603.

It is an arithmetic number, because the mean of its divisors is an integer number (779976054).

Almost surely, 2^15505616666 is an apocalyptic number.

15505616666 is a deficient number, since it is larger than the sum of its proper divisors (9453617062).

15505616666 is a wasteful number, since it uses less digits than its factorization.

15505616666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20446.

The product of its (nonzero) digits is 972000, while the sum is 47.

The spelling of 15505616666 in words is "fifteen billion, five hundred five million, six hundred sixteen thousand, six hundred sixty-six".