643552 has 72 divisors (see below), whose sum is σ = 1660176. Its totient is φ = 239616.

The previous prime is 643547. The next prime is 643553. The reversal of 643552 is 255346.

Its product of digits (3600) is a multiple of the sum of its prime factors (60).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643553) by changing a digit.

643552 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 37848 + ... + 37864.

It is an arithmetic number, because the mean of its divisors is an integer number (23058).

2⁶⁴³⁵⁵² is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 643552, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (830088).

643552 is an abundant number, since it is smaller than the sum of its proper divisors (1016624).

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

643552 is a wasteful number, since it uses less digits than its factorization.

643552 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 60 (or 39 counting only the distinct ones).

The product of its digits is 3600, while the sum is 25.

The square root of 643552 is about 802.2169282682. The cubic root of 643552 is about 86.3365217323.

Adding to 643552 its reverse (255346), we get a palindrome (898898).

The spelling of 643552 in words is "six hundred forty-three thousand, five hundred fifty-two".