643434001 has 16 divisors (see below), whose sum is σ = 742435200. Its totient is φ = 546226560.

The previous prime is 643433977. The next prime is 643434017. The reversal of 643434001 is 100434346.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 643434001 - 2⁷ = 643433873 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (643437001) by changing a digit.

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, 486421 + ... + 487741.

It is an arithmetic number, because the mean of its divisors is an integer number (46402200).

Almost surely, 2^643434001 is an apocalyptic number.

It is an amenable number.

643434001 is a deficient number, since it is larger than the sum of its proper divisors (99001199).

643434001 is a wasteful number, since it uses less digits than its factorization.

643434001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1944.

The product of its (nonzero) digits is 3456, while the sum is 25.

The square root of 643434001 is about 25366.0008870141. Note that the first 3 decimals coincide. The cubic root of 643434001 is about 863.3124464204.

Adding to 643434001 its reverse (100434346), we get a palindrome (743868347).

The spelling of 643434001 in words is "six hundred forty-three million, four hundred thirty-four thousand, one".