66388830 has 64 divisors (see below), whose sum is σ = 166328640. Its totient is φ = 16937984.

The previous prime is 66388783. The next prime is 66388849. The reversal of 66388830 is 3888366.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 118912 + ... + 119468.

It is an arithmetic number, because the mean of its divisors is an integer number (2598885).

Almost surely, 2^66388830 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66388830, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (83164320).

66388830 is an abundant number, since it is smaller than the sum of its proper divisors (99939810).

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

66388830 is a wasteful number, since it uses less digits than its factorization.

66388830 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 733.

The product of its (nonzero) digits is 165888, while the sum is 42.

The square root of 66388830 is about 8147.9340939897. The cubic root of 66388830 is about 404.9160624708.

It can be divided in two parts, 6 and 6388830, that added together give a palindrome (6388836).

The spelling of 66388830 in words is "sixty-six million, three hundred eighty-eight thousand, eight hundred thirty".