66196609 has 4 divisors (see below), whose sum is σ = 66214404. Its totient is φ = 66178816.

The previous prime is 66196597. The next prime is 66196621. The reversal of 66196609 is 90669166.

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

It is an interprime number because it is at equal distance from previous prime (66196597) and next prime (66196621).

It can be written as a sum of positive squares in 2 ways, for example, as 45265984 + 20930625 = 6728^2 + 4575^2 .

It is a cyclic number.

It is not a de Polignac number, because 66196609 - 2¹³ = 66188417 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66196639) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 952 + ... + 11545.

It is an arithmetic number, because the mean of its divisors is an integer number (16553601).

Almost surely, 2^66196609 is an apocalyptic number.

It is an amenable number.

66196609 is a deficient number, since it is larger than the sum of its proper divisors (17795).

66196609 is a wasteful number, since it uses less digits than its factorization.

66196609 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17794.

The product of its (nonzero) digits is 104976, while the sum is 43.

The square root of 66196609 is about 8136.1298539293. The cubic root of 66196609 is about 404.5248891835.

The spelling of 66196609 in words is "sixty-six million, one hundred ninety-six thousand, six hundred nine".