643855883 has 12 divisors (see below), whose sum is σ = 732117120. Its totient is φ = 565136880.

The previous prime is 643855801. The next prime is 643855889. The reversal of 643855883 is 388558346.

It is not a de Polignac number, because 643855883 - 2¹² = 643851787 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (643855889) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 88235 + ... + 95252.

It is an arithmetic number, because the mean of its divisors is an integer number (61009760).

Almost surely, 2^643855883 is an apocalyptic number.

643855883 is a deficient number, since it is larger than the sum of its proper divisors (88261237).

643855883 is a wasteful number, since it uses less digits than its factorization.

643855883 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 183538 (or 183527 counting only the distinct ones).

The product of its digits is 2764800, while the sum is 50.

The square root of 643855883 is about 25374.3154193369. The cubic root of 643855883 is about 863.5010886162.

The spelling of 643855883 in words is "six hundred forty-three million, eight hundred fifty-five thousand, eight hundred eighty-three".