643241538 has 48 divisors (see below), whose sum is σ = 1439133696. Its totient is φ = 207506880.

The previous prime is 643241531. The next prime is 643241567. The reversal of 643241538 is 835142346.

643241538 is a `hidden beast` number, since 643 + 2 + 4 + 1 + 5 + 3 + 8 = 666.

It is not an unprimeable number, because it can be changed into a prime (643241531) 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 23 ways as a sum of consecutive naturals, for example, 90295 + ... + 97157.

It is an arithmetic number, because the mean of its divisors is an integer number (29981952).

Almost surely, 2^643241538 is an apocalyptic number.

643241538 is an abundant number, since it is smaller than the sum of its proper divisors (795892158).

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

643241538 is a wasteful number, since it uses less digits than its factorization.

643241538 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7039 (or 7036 counting only the distinct ones).

The product of its digits is 69120, while the sum is 36.

The square root of 643241538 is about 25362.2068834713. The cubic root of 643241538 is about 863.2263602677.

The spelling of 643241538 in words is "six hundred forty-three million, two hundred forty-one thousand, five hundred thirty-eight".