643320032 has 12 divisors (see below), whose sum is σ = 1266536376. Its totient is φ = 321660000.

The previous prime is 643319981. The next prime is 643320037. The reversal of 643320032 is 230023346.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643320037) 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 as a sum of consecutive naturals, namely, 10051844 + ... + 10051907.

It is an arithmetic number, because the mean of its divisors is an integer number (105544698).

Almost surely, 2^643320032 is an apocalyptic number.

It is an amenable number.

643320032 is a deficient number, since it is larger than the sum of its proper divisors (623216344).

643320032 is a wasteful number, since it uses less digits than its factorization.

643320032 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20103761 (or 20103753 counting only the distinct ones).

The product of its (nonzero) digits is 2592, while the sum is 23.

The square root of 643320032 is about 25363.7542962393. The cubic root of 643320032 is about 863.2614716683.

Adding to 643320032 its reverse (230023346), we get a palindrome (873343378).

The spelling of 643320032 in words is "six hundred forty-three million, three hundred twenty thousand, thirty-two".