66564409 has 8 divisors (see below), whose sum is σ = 69177600. Its totient is φ = 63980400.

The previous prime is 66564397. The next prime is 66564427. The reversal of 66564409 is 90446566.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 66564409 - 2²¹ = 64467257 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66564499) 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 7 ways as a sum of consecutive naturals, for example, 2587 + ... + 11824.

It is an arithmetic number, because the mean of its divisors is an integer number (8647200).

Almost surely, 2^66564409 is an apocalyptic number.

It is an amenable number.

66564409 is a deficient number, since it is larger than the sum of its proper divisors (2613191).

66564409 is a wasteful number, since it uses less digits than its factorization.

66564409 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14591.

The product of its (nonzero) digits is 155520, while the sum is 40.

The square root of 66564409 is about 8158.7014285363. The cubic root of 66564409 is about 405.2727096875.

The spelling of 66564409 in words is "sixty-six million, five hundred sixty-four thousand, four hundred nine".