6659406605 has 4 divisors (see below), whose sum is σ = 7991287932. Its totient is φ = 5327525280.

The previous prime is 6659406581. The next prime is 6659406623. The reversal of 6659406605 is 5066049566.

It is a happy number.

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 3066722884 + 3592683721 = 55378^2 + 59939^2 .

It is not a de Polignac number, because 6659406605 - 2⁶ = 6659406541 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 6659406605.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 665940656 + ... + 665940665.

It is an arithmetic number, because the mean of its divisors is an integer number (1997821983).

Almost surely, 2^6659406605 is an apocalyptic number.

It is an amenable number.

6659406605 is a deficient number, since it is larger than the sum of its proper divisors (1331881327).

6659406605 is a wasteful number, since it uses less digits than its factorization.

6659406605 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1331881326.

The product of its (nonzero) digits is 1166400, while the sum is 47.

The square root of 6659406605 is about 81605.1873657551. The cubic root of 6659406605 is about 1881.3886116489.

The spelling of 6659406605 in words is "six billion, six hundred fifty-nine million, four hundred six thousand, six hundred five".