66520671866 has 32 divisors (see below), whose sum is σ = 115495994880. Its totient is φ = 28398553600.

The previous prime is 66520671827. The next prime is 66520671911. The reversal of 66520671866 is 66817602566.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 6515 + ... + 364806.

It is an arithmetic number, because the mean of its divisors is an integer number (3609249840).

Almost surely, 2^66520671866 is an apocalyptic number.

66520671866 is a deficient number, since it is larger than the sum of its proper divisors (48975323014).

66520671866 is a wasteful number, since it uses less digits than its factorization.

66520671866 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 371830.

The product of its (nonzero) digits is 4354560, while the sum is 53.

The spelling of 66520671866 in words is "sixty-six billion, five hundred twenty million, six hundred seventy-one thousand, eight hundred sixty-six".