66664872 has 24 divisors (see below), whose sum is σ = 180550890. Its totient is φ = 22221600.

The previous prime is 66664859. The next prime is 66664883. The reversal of 66664872 is 27846666.

It can be written as a sum of positive squares in only one way, i.e., 60933636 + 5731236 = 7806^2 + 2394^2 .

It is a tau number, because it is divible by the number of its divisors (24).

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 462879 + ... + 463022.

Almost surely, 2^66664872 is an apocalyptic number.

It is an amenable number.

66664872 is an abundant number, since it is smaller than the sum of its proper divisors (113886018).

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

66664872 is a wasteful number, since it uses less digits than its factorization.

66664872 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 925913 (or 925906 counting only the distinct ones).

The product of its digits is 580608, while the sum is 45.

The square root of 66664872 is about 8164.8559080978. The cubic root of 66664872 is about 405.4764944972.

The spelling of 66664872 in words is "sixty-six million, six hundred sixty-four thousand, eight hundred seventy-two".