66795409 has 4 divisors (see below), whose sum is σ = 66884404. Its totient is φ = 66706416.

The previous prime is 66795403. The next prime is 66795419. The reversal of 66795409 is 90459766.

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 34339600 + 32455809 = 5860^2 + 5697^2 .

It is a cyclic number.

It is not a de Polignac number, because 66795409 - 2³ = 66795401 is a prime.

It is a super-3 number, since 3×66795409³ (a number of 24 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66795401) 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, 43362 + ... + 44875.

It is an arithmetic number, because the mean of its divisors is an integer number (16721101).

Almost surely, 2^66795409 is an apocalyptic number.

It is an amenable number.

66795409 is a deficient number, since it is larger than the sum of its proper divisors (88995).

66795409 is an equidigital number, since it uses as much as digits as its factorization.

66795409 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 88994.

The product of its (nonzero) digits is 408240, while the sum is 46.

The square root of 66795409 is about 8172.8458323891. The cubic root of 66795409 is about 405.7409774938.

The spelling of 66795409 in words is "sixty-six million, seven hundred ninety-five thousand, four hundred nine".