66289813 has 4 divisors (see below), whose sum is σ = 66339468. Its totient is φ = 66240160.

The previous prime is 66289801. The next prime is 66289823. The reversal of 66289813 is 31898266.

66289813 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 31898266 = 2 ⋅15949133.

It can be written as a sum of positive squares in 2 ways, for example, as 52099524 + 14190289 = 7218^2 + 3767^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66289813 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 66289813.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66289823) by changing a digit.

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, 22768 + ... + 25513.

It is an arithmetic number, because the mean of its divisors is an integer number (16584867).

Almost surely, 2^66289813 is an apocalyptic number.

It is an amenable number.

66289813 is a deficient number, since it is larger than the sum of its proper divisors (49655).

66289813 is a wasteful number, since it uses less digits than its factorization.

66289813 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 49654.

The product of its digits is 124416, while the sum is 43.

The square root of 66289813 is about 8141.8556238735. The cubic root of 66289813 is about 404.7146554816.

The spelling of 66289813 in words is "sixty-six million, two hundred eighty-nine thousand, eight hundred thirteen".