66643272 has 48 divisors (see below), whose sum is σ = 181818000. Its totient is φ = 22051296.

The previous prime is 66643271. The next prime is 66643277. The reversal of 66643272 is 27234666.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (66643271) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 6679 + ... + 13337.

It is an arithmetic number, because the mean of its divisors is an integer number (3787875).

Almost surely, 2^66643272 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 66643272, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (90909000).

66643272 is an abundant number, since it is smaller than the sum of its proper divisors (115174728).

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

66643272 is a wasteful number, since it uses less digits than its factorization.

66643272 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6810 (or 6803 counting only the distinct ones).

The product of its digits is 72576, while the sum is 36.

The square root of 66643272 is about 8163.5330586701. The cubic root of 66643272 is about 405.4326971263.

The spelling of 66643272 in words is "sixty-six million, six hundred forty-three thousand, two hundred seventy-two".