643275655 has 16 divisors (see below), whose sum is σ = 842784768. Its totient is φ = 467460000.

The previous prime is 643275653. The next prime is 643275671. The reversal of 643275655 is 556572346.

It is not a de Polignac number, because 643275655 - 2¹ = 643275653 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643275653) by changing a digit.

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, 76930 + ... + 84880.

It is an arithmetic number, because the mean of its divisors is an integer number (52674048).

Almost surely, 2^643275655 is an apocalyptic number.

643275655 is a deficient number, since it is larger than the sum of its proper divisors (199509113).

643275655 is a wasteful number, since it uses less digits than its factorization.

643275655 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9438.

The product of its digits is 756000, while the sum is 43.

The square root of 643275655 is about 25362.8794698078. The cubic root of 643275655 is about 863.2416216024.

The spelling of 643275655 in words is "six hundred forty-three million, two hundred seventy-five thousand, six hundred fifty-five".