643086655 has 8 divisors (see below), whose sum is σ = 774339552. Its totient is φ = 512712288.

The previous prime is 643086649. The next prime is 643086679. The reversal of 643086655 is 556680346.

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 643086655 - 2⁷ = 643086527 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, 218019 + ... + 220948.

It is an arithmetic number, because the mean of its divisors is an integer number (96792444).

Almost surely, 2^643086655 is an apocalyptic number.

643086655 is a deficient number, since it is larger than the sum of its proper divisors (131252897).

643086655 is a wasteful number, since it uses less digits than its factorization.

643086655 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 439265.

The product of its (nonzero) digits is 518400, while the sum is 43.

The square root of 643086655 is about 25359.1532784516. The cubic root of 643086655 is about 863.1570706812.

The spelling of 643086655 in words is "six hundred forty-three million, eighty-six thousand, six hundred fifty-five".