6434720643 has 32 divisors (see below), whose sum is σ = 9789728256. Its totient is φ = 3724374528.

The previous prime is 6434720639. The next prime is 6434720657. The reversal of 6434720643 is 3460274346.

It is not a de Polignac number, because 6434720643 - 2² = 6434720639 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is not an unprimeable number, because it can be changed into a prime (6434722643) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1484946 + ... + 1489272.

It is an arithmetic number, because the mean of its divisors is an integer number (305929008).

Almost surely, 2^6434720643 is an apocalyptic number.

6434720643 is a deficient number, since it is larger than the sum of its proper divisors (3355007613).

6434720643 is a wasteful number, since it uses less digits than its factorization.

6434720643 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6603.

The product of its (nonzero) digits is 290304, while the sum is 39.

The square root of 6434720643 is about 80216.7104972524. The cubic root of 6434720643 is about 1859.9869582274.

Adding to 6434720643 its reverse (3460274346), we get a palindrome (9894994989).

The spelling of 6434720643 in words is "six billion, four hundred thirty-four million, seven hundred twenty thousand, six hundred forty-three".