66381320 has 16 divisors (see below), whose sum is σ = 149358060. Its totient is φ = 26552512.

The previous prime is 66381299. The next prime is 66381347. The reversal of 66381320 is 2318366.

66381320 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 54671236 + 11710084 = 7394^2 + 3422^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 829727 + ... + 829806.

Almost surely, 2^66381320 is an apocalyptic number.

It is an amenable number.

66381320 is an abundant number, since it is smaller than the sum of its proper divisors (82976740).

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

66381320 is a wasteful number, since it uses less digits than its factorization.

66381320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1659544 (or 1659540 counting only the distinct ones).

The product of its (nonzero) digits is 5184, while the sum is 29.

The square root of 66381320 is about 8147.4732279401. The cubic root of 66381320 is about 404.9007936657.

Adding to 66381320 its reverse (2318366), we get a palindrome (68699686).

The spelling of 66381320 in words is "sixty-six million, three hundred eighty-one thousand, three hundred twenty".