646255206566 has 16 divisors (see below), whose sum is σ = 1004784224256. Its totient is φ = 311532357576.

The previous prime is 646255206559. The next prime is 646255206607. The reversal of 646255206566 is 665602552646.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 51300086 + ... + 51312681.

It is an arithmetic number, because the mean of its divisors is an integer number (62799014016).

Almost surely, 2^646255206566 is an apocalyptic number.

646255206566 is a deficient number, since it is larger than the sum of its proper divisors (358529017690).

646255206566 is a wasteful number, since it uses less digits than its factorization.

646255206566 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 102612883.

The product of its (nonzero) digits is 15552000, while the sum is 53.

The spelling of 646255206566 in words is "six hundred forty-six billion, two hundred fifty-five million, two hundred six thousand, five hundred sixty-six".