66564413 has 4 divisors (see below), whose sum is σ = 66614268. Its totient is φ = 66514560.

The previous prime is 66564397. The next prime is 66564427. The reversal of 66564413 is 31446566.

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 65966884 + 597529 = 8122^2 + 773^2 .

It is a cyclic number.

It is not a de Polignac number, because 66564413 - 2⁴ = 66564397 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66564493) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 22868 + ... + 25613.

It is an arithmetic number, because the mean of its divisors is an integer number (16653567).

Almost surely, 2^66564413 is an apocalyptic number.

It is an amenable number.

66564413 is a deficient number, since it is larger than the sum of its proper divisors (49855).

66564413 is a wasteful number, since it uses less digits than its factorization.

66564413 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 49854.

The product of its digits is 51840, while the sum is 35.

The square root of 66564413 is about 8158.7016736733. The cubic root of 66564413 is about 405.2727178054.

The spelling of 66564413 in words is "sixty-six million, five hundred sixty-four thousand, four hundred thirteen".