66173856384 has 64 divisors (see below), whose sum is σ = 179090857440. Its totient is φ = 21641757696.

The previous prime is 66173856361. The next prime is 66173856389. The reversal of 66173856384 is 48365837166.

It is a tau number, because it is divible by the number of its divisors (64).

It is not an unprimeable number, because it can be changed into a prime (66173856389) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1605382 + ... + 1646085.

Almost surely, 2^66173856384 is an apocalyptic number.

66173856384 is a gapful number since it is divisible by the number (64) formed by its first and last digit.

It is an amenable number.

66173856384 is an abundant number, since it is smaller than the sum of its proper divisors (112917001056).

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

66173856384 is a wasteful number, since it uses less digits than its factorization.

66173856384 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3251537 (or 3251525 counting only the distinct ones).

The product of its digits is 17418240, while the sum is 57.

The spelling of 66173856384 in words is "sixty-six billion, one hundred seventy-three million, eight hundred fifty-six thousand, three hundred eighty-four".