66203720 has 64 divisors (see below), whose sum is σ = 163339200. Its totient is φ = 23950080.

The previous prime is 66203707. The next prime is 66203741. The reversal of 66203720 is 2730266.

It is a self number, because there is not a number n which added to its sum of digits gives 66203720.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 166562 + ... + 166958.

It is an arithmetic number, because the mean of its divisors is an integer number (2552175).

Almost surely, 2^66203720 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 66203720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (81669600).

66203720 is an abundant number, since it is smaller than the sum of its proper divisors (97135480).

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

66203720 is a wasteful number, since it uses less digits than its factorization.

66203720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 798 (or 794 counting only the distinct ones).

The product of its (nonzero) digits is 3024, while the sum is 26.

The square root of 66203720 is about 8136.5668435772. The cubic root of 66203720 is about 404.5393736791.

Adding to 66203720 its reverse (2730266), we get a palindrome (68933986).

The spelling of 66203720 in words is "sixty-six million, two hundred three thousand, seven hundred twenty".