51605516666 has 32 divisors (see below), whose sum is σ = 88646952960. Its totient is φ = 22315604400.

The previous prime is 51605516639. The next prime is 51605516671. The reversal of 51605516666 is 66661550615.

It is a Smith number, since the sum of its digits (47) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a self number, because there is not a number n which added to its sum of digits gives 51605516666.

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, 601016 + ... + 681491.

It is an arithmetic number, because the mean of its divisors is an integer number (2770217280).

Almost surely, 2^51605516666 is an apocalyptic number.

51605516666 is a deficient number, since it is larger than the sum of its proper divisors (37041436294).

51605516666 is a wasteful number, since it uses less digits than its factorization.

51605516666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1282610.

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

The spelling of 51605516666 in words is "fifty-one billion, six hundred five million, five hundred sixteen thousand, six hundred sixty-six".