505666001666 has 16 divisors (see below), whose sum is σ = 866921513856. Its totient is φ = 216697622976.

The previous prime is 505666001629. The next prime is 505666001669. The reversal of 505666001666 is 666100666505.

It is a super-2 number, since 2×505666001666² (a number of 24 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 505666001666.

It is not an unprimeable number, because it can be changed into a prime (505666001669) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 1172006 + ... + 1544321.

It is an arithmetic number, because the mean of its divisors is an integer number (54182594616).

Almost surely, 2^505666001666 is an apocalyptic number.

505666001666 is a deficient number, since it is larger than the sum of its proper divisors (361255512190).

505666001666 is a wasteful number, since it uses less digits than its factorization.

505666001666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2729633.

The product of its (nonzero) digits is 1166400, while the sum is 47.

The spelling of 505666001666 in words is "five hundred five billion, six hundred sixty-six million, one thousand, six hundred sixty-six".