643241540 has 48 divisors (see below), whose sum is σ = 1390483584. Its totient is φ = 249849600.

The previous prime is 643241531. The next prime is 643241567. The reversal of 643241540 is 45142346.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 91760 + ... + 98520.

It is an arithmetic number, because the mean of its divisors is an integer number (28968408).

Almost surely, 2^643241540 is an apocalyptic number.

It is an amenable number.

643241540 is an abundant number, since it is smaller than the sum of its proper divisors (747242044).

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

643241540 is a wasteful number, since it uses less digits than its factorization.

643241540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6908 (or 6906 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 29.

The square root of 643241540 is about 25362.2069229001. The cubic root of 643241540 is about 863.2263611624.

Adding to 643241540 its reverse (45142346), we get a palindrome (688383886).

The spelling of 643241540 in words is "six hundred forty-three million, two hundred forty-one thousand, five hundred forty".