66984812173 has 12 divisors (see below), whose sum is σ = 73080047092. Its totient is φ = 61340613120.

The previous prime is 66984812159. The next prime is 66984812203. The reversal of 66984812173 is 37121848966.

It can be written as a sum of positive squares in 6 ways, for example, as 4343732649 + 62641079524 = 65907^2 + 250282^2 .

It is not a de Polignac number, because 66984812173 - 2²¹ = 66982715021 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66984822173) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3121488 + ... + 3142873.

Almost surely, 2^66984812173 is an apocalyptic number.

It is an amenable number.

66984812173 is a deficient number, since it is larger than the sum of its proper divisors (6095234919).

66984812173 is a wasteful number, since it uses less digits than its factorization.

66984812173 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6264432 (or 6264415 counting only the distinct ones).

The product of its digits is 3483648, while the sum is 55.

The spelling of 66984812173 in words is "sixty-six billion, nine hundred eighty-four million, eight hundred twelve thousand, one hundred seventy-three".