66447872 has 40 divisors (see below), whose sum is σ = 133575156. Its totient is φ = 33021952.

The previous prime is 66447869. The next prime is 66447881. The reversal of 66447872 is 27874466.

66447872 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 56310016 + 10137856 = 7504^2 + 3184^2 .

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 in 3 ways as a sum of consecutive naturals, for example, 119018 + ... + 119574.

Almost surely, 2^66447872 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66447872, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (66787578).

66447872 is an abundant number, since it is smaller than the sum of its proper divisors (67127284).

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

66447872 is an equidigital number, since it uses as much as digits as its factorization.

66447872 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 808 (or 792 counting only the distinct ones).

The product of its digits is 451584, while the sum is 44.

The square root of 66447872 is about 8151.5564158018. The cubic root of 66447872 is about 405.0360624292.

The spelling of 66447872 in words is "sixty-six million, four hundred forty-seven thousand, eight hundred seventy-two".