66386628 has 144 divisors (see below), whose sum is σ = 217211904. Its totient is φ = 17223840.

The previous prime is 66386611. The next prime is 66386647. The reversal of 66386628 is 82668366.

66386628 is a `hidden beast` number, since 6 + 638 + 6 + 6 + 2 + 8 = 666.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 74401 + ... + 75287.

It is an arithmetic number, because the mean of its divisors is an integer number (1508416).

Almost surely, 2^66386628 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 66386628, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (108605952).

66386628 is an abundant number, since it is smaller than the sum of its proper divisors (150825276).

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

66386628 is a wasteful number, since it uses less digits than its factorization.

66386628 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 924 (or 910 counting only the distinct ones).

The product of its digits is 497664, while the sum is 45.

The square root of 66386628 is about 8147.7989665921. The cubic root of 66386628 is about 404.9115856382.

The spelling of 66386628 in words is "sixty-six million, three hundred eighty-six thousand, six hundred twenty-eight".