66646872 has 96 divisors (see below), whose sum is σ = 190242000. Its totient is φ = 21047040.

The previous prime is 66646829. The next prime is 66646897. The reversal of 66646872 is 27864666.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 122922 + ... + 123462.

Almost surely, 2^66646872 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 66646872, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (95121000).

66646872 is an abundant number, since it is smaller than the sum of its proper divisors (123595128).

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

66646872 is a wasteful number, since it uses less digits than its factorization.

66646872 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 641 (or 634 counting only the distinct ones).

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

The square root of 66646872 is about 8163.7535484604. The cubic root of 66646872 is about 405.4399973452.

The spelling of 66646872 in words is "sixty-six million, six hundred forty-six thousand, eight hundred seventy-two".