66870172 has 24 divisors (see below), whose sum is σ = 121564800. Its totient is φ = 32147136.

The previous prime is 66870161. The next prime is 66870179. The reversal of 66870172 is 27107866.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66870179) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 30133 + ... + 32275.

It is an arithmetic number, because the mean of its divisors is an integer number (5065200).

Almost surely, 2^66870172 is an apocalyptic number.

It is an amenable number.

66870172 is a deficient number, since it is larger than the sum of its proper divisors (54694628).

66870172 is a wasteful number, since it uses less digits than its factorization.

66870172 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2445 (or 2443 counting only the distinct ones).

The product of its (nonzero) digits is 28224, while the sum is 37.

The square root of 66870172 is about 8177.4184190367. The cubic root of 66870172 is about 405.8923007788.

The spelling of 66870172 in words is "sixty-six million, eight hundred seventy thousand, one hundred seventy-two".