66389328 has 80 divisors (see below), whose sum is σ = 191684160. Its totient is φ = 21999744.

The previous prime is 66389299. The next prime is 66389329. The reversal of 66389328 is 82398366.

66389328 is a `hidden beast` number, since 6 + 638 + 9 + 3 + 2 + 8 = 666.

It is a nude number because it is divisible by every one of its digits.

It is a zygodrome in base 4.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66389329) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 97726 + ... + 98402.

It is an arithmetic number, because the mean of its divisors is an integer number (2396052).

Almost surely, 2^66389328 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 66389328, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (95842080).

66389328 is an abundant number, since it is smaller than the sum of its proper divisors (125294832).

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

66389328 is a wasteful number, since it uses less digits than its factorization.

66389328 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 921 (or 909 counting only the distinct ones).

The product of its digits is 373248, while the sum is 45.

The square root of 66389328 is about 8147.9646538261. The cubic root of 66389328 is about 404.9170749287.

The spelling of 66389328 in words is "sixty-six million, three hundred eighty-nine thousand, three hundred twenty-eight".