646332385609 has 8 divisors (see below), whose sum is σ = 647219923272. Its totient is φ = 645445342080.

The previous prime is 646332385591. The next prime is 646332385613. The reversal of 646332385609 is 906583233646.

It can be written as a sum of positive squares in 4 ways, for example, as 157351055625 + 488981329984 = 396675^2 + 699272^2 .

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 646332385609 - 2¹⁹ = 646331861321 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 646332385609.

It is not an unprimeable number, because it can be changed into a prime (646332325609) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 2533357 + ... + 2776789.

It is an arithmetic number, because the mean of its divisors is an integer number (80902490409).

Almost surely, 2^646332385609 is an apocalyptic number.

It is an amenable number.

646332385609 is a deficient number, since it is larger than the sum of its proper divisors (887537663).

646332385609 is a wasteful number, since it uses less digits than its factorization.

646332385609 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 247067.

The product of its (nonzero) digits is 16796160, while the sum is 55.

The spelling of 646332385609 in words is "six hundred forty-six billion, three hundred thirty-two million, three hundred eighty-five thousand, six hundred nine".