66694516545 has 32 divisors (see below), whose sum is σ = 107480649600. Its totient is φ = 35314173440.

The previous prime is 66694516513. The next prime is 66694516571. The reversal of 66694516545 is 54561549666.

It is not a de Polignac number, because 66694516545 - 2⁵ = 66694516513 is a prime.

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 31 ways as a sum of consecutive naturals, for example, 5382397 + ... + 5394773.

It is an arithmetic number, because the mean of its divisors is an integer number (3358770300).

Almost surely, 2^66694516545 is an apocalyptic number.

It is an amenable number.

66694516545 is a deficient number, since it is larger than the sum of its proper divisors (40786133055).

66694516545 is a wasteful number, since it uses less digits than its factorization.

66694516545 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14945.

The product of its digits is 23328000, while the sum is 57.

The spelling of 66694516545 in words is "sixty-six billion, six hundred ninety-four million, five hundred sixteen thousand, five hundred forty-five".