66338609 has 4 divisors (see below), whose sum is σ = 66958704. Its totient is φ = 65718516.

The previous prime is 66338603. The next prime is 66338681. The reversal of 66338609 is 90683366.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 66338609 - 2⁴ = 66338593 is a prime.

It is a super-2 number, since 2×66338609² = 8801622088109762, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66338603) 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, 309887 + ... + 310100.

It is an arithmetic number, because the mean of its divisors is an integer number (16739676).

Almost surely, 2^66338609 is an apocalyptic number.

It is an amenable number.

66338609 is a deficient number, since it is larger than the sum of its proper divisors (620095).

66338609 is a wasteful number, since it uses less digits than its factorization.

66338609 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 620094.

The product of its (nonzero) digits is 139968, while the sum is 41.

The square root of 66338609 is about 8144.8516868019. The cubic root of 66338609 is about 404.8139347514.

The spelling of 66338609 in words is "sixty-six million, three hundred thirty-eight thousand, six hundred nine".