664818243205 has 8 divisors (see below), whose sum is σ = 804841909272. Its totient is φ = 527147916288.

The previous prime is 664818243197. The next prime is 664818243251. The reversal of 664818243205 is 502342818466.

It can be written as a sum of positive squares in 4 ways, for example, as 10495797601 + 654322445604 = 102449^2 + 808902^2 .

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 664818243205 - 2³ = 664818243197 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

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, 588334164 + ... + 588335293.

It is an arithmetic number, because the mean of its divisors is an integer number (100605238659).

Almost surely, 2^664818243205 is an apocalyptic number.

It is an amenable number.

664818243205 is a deficient number, since it is larger than the sum of its proper divisors (140023666067).

664818243205 is a wasteful number, since it uses less digits than its factorization.

664818243205 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1176669575.

The product of its (nonzero) digits is 2211840, while the sum is 49.

The spelling of 664818243205 in words is "six hundred sixty-four billion, eight hundred eighteen million, two hundred forty-three thousand, two hundred five".