66864172 has 6 divisors (see below), whose sum is σ = 117012308. Its totient is φ = 33432084.

The previous prime is 66864139. The next prime is 66864181. The reversal of 66864172 is 27146866.

66864172 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8358018 + ... + 8358025.

Almost surely, 2^66864172 is an apocalyptic number.

It is an amenable number.

66864172 is a deficient number, since it is larger than the sum of its proper divisors (50148136).

66864172 is a wasteful number, since it uses less digits than its factorization.

66864172 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16716047 (or 16716045 counting only the distinct ones).

The product of its digits is 96768, while the sum is 40.

The square root of 66864172 is about 8177.0515468597. The cubic root of 66864172 is about 405.8801607041.

The spelling of 66864172 in words is "sixty-six million, eight hundred sixty-four thousand, one hundred seventy-two".