643611552 has 48 divisors (see below), whose sum is σ = 1695828960. Its totient is φ = 213731072.

The previous prime is 643611547. The next prime is 643611593. The reversal of 643611552 is 255116346.

643611552 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (48).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13363 + ... + 38285.

It is an arithmetic number, because the mean of its divisors is an integer number (35329770).

Almost surely, 2^643611552 is an apocalyptic number.

It is an amenable number.

643611552 is an abundant number, since it is smaller than the sum of its proper divisors (1052217408).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

643611552 is a wasteful number, since it uses less digits than its factorization.

643611552 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25205 (or 25197 counting only the distinct ones).

The product of its digits is 21600, while the sum is 33.

The square root of 643611552 is about 25369.5004286643. The cubic root of 643611552 is about 863.3918474110.

Adding to 643611552 its reverse (255116346), we get a palindrome (898727898).

The spelling of 643611552 in words is "six hundred forty-three million, six hundred eleven thousand, five hundred fifty-two".