643643243401 has 24 divisors (see below), whose sum is σ = 704541920640. Its totient is φ = 586336177440.

The previous prime is 643643243381. The next prime is 643643243423. The reversal of 643643243401 is 104342346346.

It is not a de Polignac number, because 643643243401 - 2⁹ = 643643242889 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (643643243431) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2754400 + ... + 2978926.

It is an arithmetic number, because the mean of its divisors is an integer number (29355913360).

Almost surely, 2^643643243401 is an apocalyptic number.

It is an amenable number.

643643243401 is a deficient number, since it is larger than the sum of its proper divisors (60898677239).

643643243401 is a wasteful number, since it uses less digits than its factorization.

643643243401 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 224765 (or 224734 counting only the distinct ones).

The product of its (nonzero) digits is 497664, while the sum is 40.

Adding to 643643243401 its reverse (104342346346), we get a palindrome (747985589747).

The spelling of 643643243401 in words is "six hundred forty-three billion, six hundred forty-three million, two hundred forty-three thousand, four hundred one".