643240041 has 32 divisors (see below), whose sum is σ = 919910400. Its totient is φ = 398623680.

The previous prime is 643240009. The next prime is 643240043. The reversal of 643240041 is 140042346.

It is not a de Polignac number, because 643240041 - 2⁵ = 643240009 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 643239993 and 643240020.

It is not an unprimeable number, because it can be changed into a prime (643240043) 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 31 ways as a sum of consecutive naturals, for example, 949795 + ... + 950471.

It is an arithmetic number, because the mean of its divisors is an integer number (28747200).

Almost surely, 2^643240041 is an apocalyptic number.

It is an amenable number.

643240041 is a deficient number, since it is larger than the sum of its proper divisors (276670359).

643240041 is a wasteful number, since it uses less digits than its factorization.

643240041 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 989.

The product of its (nonzero) digits is 2304, while the sum is 24.

The square root of 643240041 is about 25362.1773710382. The cubic root of 643240041 is about 863.2256906121.

Adding to 643240041 its reverse (140042346), we get a palindrome (783282387).

The spelling of 643240041 in words is "six hundred forty-three million, two hundred forty thousand, forty-one".