646326225665 has 16 divisors (see below), whose sum is σ = 821305636560. Its totient is φ = 486591621120.

The previous prime is 646326225619. The next prime is 646326225689. The reversal of 646326225665 is 566522623646.

It can be written as a sum of positive squares in 8 ways, for example, as 100912958224 + 545413267441 = 317668^2 + 738521^2 .

It is not a de Polignac number, because 646326225665 - 2¹⁰ = 646326224641 is a prime.

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 15 ways as a sum of consecutive naturals, for example, 356885 + ... + 1191645.

It is an arithmetic number, because the mean of its divisors is an integer number (51331602285).

Almost surely, 2^646326225665 is an apocalyptic number.

It is an amenable number.

646326225665 is a deficient number, since it is larger than the sum of its proper divisors (174979410895).

646326225665 is a wasteful number, since it uses less digits than its factorization.

646326225665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 843892.

The product of its digits is 18662400, while the sum is 53.

The spelling of 646326225665 in words is "six hundred forty-six billion, three hundred twenty-six million, two hundred twenty-five thousand, six hundred sixty-five".