666505359855 has 12 divisors (see below), whose sum is σ = 1155275957160. Its totient is φ = 355469525232.

The previous prime is 666505359851. The next prime is 666505359887. The reversal of 666505359855 is 558953505666.

It is not a de Polignac number, because 666505359855 - 2² = 666505359851 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 666505359792 and 666505359801.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (666505359851) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 7405615065 + ... + 7405615154.

It is an arithmetic number, because the mean of its divisors is an integer number (96272996430).

Almost surely, 2^666505359855 is an apocalyptic number.

666505359855 is a deficient number, since it is larger than the sum of its proper divisors (488770597305).

666505359855 is a wasteful number, since it uses less digits than its factorization.

666505359855 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14811230230 (or 14811230227 counting only the distinct ones).

The product of its (nonzero) digits is 145800000, while the sum is 63.

The spelling of 666505359855 in words is "six hundred sixty-six billion, five hundred five million, three hundred fifty-nine thousand, eight hundred fifty-five".