66044813 has 4 divisors (see below), whose sum is σ = 69929820. Its totient is φ = 62159808.

The previous prime is 66044807. The next prime is 66044827. The reversal of 66044813 is 31844066.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 27269284 + 38775529 = 5222^2 + 6227^2 .

It is a cyclic number.

It is not a de Polignac number, because 66044813 - 2⁶ = 66044749 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 66044813.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66044863) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1942478 + ... + 1942511.

It is an arithmetic number, because the mean of its divisors is an integer number (17482455).

Almost surely, 2^66044813 is an apocalyptic number.

It is an amenable number.

66044813 is a deficient number, since it is larger than the sum of its proper divisors (3885007).

66044813 is a wasteful number, since it uses less digits than its factorization.

66044813 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3885006.

The product of its (nonzero) digits is 13824, while the sum is 32.

The square root of 66044813 is about 8126.7959861190. The cubic root of 66044813 is about 404.2154460604.

Adding to 66044813 its reverse (31844066), we get a palindrome (97888879).

The spelling of 66044813 in words is "sixty-six million, forty-four thousand, eight hundred thirteen".