643353312 has 96 divisors (see below), whose sum is σ = 1937779200. Its totient is φ = 183080448.

The previous prime is 643353301. The next prime is 643353329. The reversal of 643353312 is 213353346.

It is a tau number, because it is divible by the number of its divisors (96).

It is a super-2 number, since 2×643353312² = 827806968122738688, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 643353312.

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 15 ways as a sum of consecutive naturals, for example, 178989 + ... + 182547.

It is an arithmetic number, because the mean of its divisors is an integer number (20185200).

Almost surely, 2^643353312 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 643353312, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (968889600).

643353312 is an abundant number, since it is smaller than the sum of its proper divisors (1294425888).

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

643353312 is a wasteful number, since it uses less digits than its factorization.

643353312 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3848 (or 3840 counting only the distinct ones).

The product of its digits is 19440, while the sum is 30.

The square root of 643353312 is about 25364.4103420521. The cubic root of 643353312 is about 863.2763573887.

The spelling of 643353312 in words is "six hundred forty-three million, three hundred fifty-three thousand, three hundred twelve".