66391680672 has 96 divisors (see below), whose sum is σ = 195522687360. Its totient is φ = 21915671040.

The previous prime is 66391680637. The next prime is 66391680709. The reversal of 66391680672 is 27608619366.

It is a tau number, because it is divible by the number of its divisors (96).

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 284029 + ... + 462012.

It is an arithmetic number, because the mean of its divisors is an integer number (2036694660).

Almost surely, 2^66391680672 is an apocalyptic number.

It is an amenable number.

66391680672 is an abundant number, since it is smaller than the sum of its proper divisors (129131006688).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

66391680672 is a wasteful number, since it uses less digits than its factorization.

66391680672 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 746163 (or 746149 counting only the distinct ones).

The product of its (nonzero) digits is 3919104, while the sum is 54.

The spelling of 66391680672 in words is "sixty-six billion, three hundred ninety-one million, six hundred eighty thousand, six hundred seventy-two".