643313552 has 90 divisors (see below), whose sum is σ = 1530918198. Its totient is φ = 261080064.

The previous prime is 643313549. The next prime is 643313563. The reversal of 643313552 is 255313346.

It can be written as a sum of positive squares in only one way, i.e., 625200016 + 18113536 = 25004^2 + 4256^2 .

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 281888 + ... + 284160.

Almost surely, 2^643313552 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 643313552, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (765459099).

643313552 is an abundant number, since it is smaller than the sum of its proper divisors (887604646).

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

643313552 is a wasteful number, since it uses less digits than its factorization.

643313552 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2333 (or 2301 counting only the distinct ones).

The product of its digits is 32400, while the sum is 32.

The square root of 643313552 is about 25363.6265545761. The cubic root of 643313552 is about 863.2585731871.

Adding to 643313552 its reverse (255313346), we get a palindrome (898626898).

The spelling of 643313552 in words is "six hundred forty-three million, three hundred thirteen thousand, five hundred fifty-two".