643858842 has 32 divisors (see below), whose sum is σ = 1414909440. Its totient is φ = 193702320.

The previous prime is 643858837. The next prime is 643858903. The reversal of 643858842 is 248858346.

It is a junction number, because it is equal to n+sod(n) for n = 643858791 and 643858800.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 25918 + ... + 44265.

It is an arithmetic number, because the mean of its divisors is an integer number (44215920).

Almost surely, 2^643858842 is an apocalyptic number.

643858842 is an abundant number, since it is smaller than the sum of its proper divisors (771050598).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

643858842 is a wasteful number, since it uses less digits than its factorization.

643858842 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 70338.

The product of its digits is 1474560, while the sum is 48.

The square root of 643858842 is about 25374.3737262617. The cubic root of 643858842 is about 863.5024114255.

The spelling of 643858842 in words is "six hundred forty-three million, eight hundred fifty-eight thousand, eight hundred forty-two".