66351631615664 has 20 divisors (see below), whose sum is σ = 128659213665000. Its totient is φ = 33149253895680.

The previous prime is 66351631615657. The next prime is 66351631615667. The reversal of 66351631615664 is 46651613615366.

66351631615664 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Smith number, since the sum of its digits (59) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (66351631615667) 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 3 ways as a sum of consecutive naturals, for example, 1660098902 + ... + 1660138869.

It is an arithmetic number, because the mean of its divisors is an integer number (6432960683250).

Almost surely, 2^{66351631615664} is an apocalyptic number.

It is an amenable number.

66351631615664 is a deficient number, since it is larger than the sum of its proper divisors (62307582049336).

66351631615664 is a wasteful number, since it uses less digits than its factorization.

66351631615664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3320239028 (or 3320239022 counting only the distinct ones).

The product of its digits is 41990400, while the sum is 59.

The spelling of 66351631615664 in words is "sixty-six trillion, three hundred fifty-one billion, six hundred thirty-one million, six hundred fifteen thousand, six hundred sixty-four".