643297368 has 128 divisors (see below), whose sum is σ = 1912320000. Its totient is φ = 176463360.

The previous prime is 643297367. The next prime is 643297397. The reversal of 643297368 is 863792346.

643297368 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-3 number, since 3×643297368³ (a number of 27 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643297367) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 775578 + ... + 776406.

It is an arithmetic number, because the mean of its divisors is an integer number (14940000).

Almost surely, 2^643297368 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 643297368, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (956160000).

643297368 is an abundant number, since it is smaller than the sum of its proper divisors (1269022632).

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

643297368 is a wasteful number, since it uses less digits than its factorization.

643297368 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1025 (or 1021 counting only the distinct ones).

The product of its digits is 1306368, while the sum is 48.

The square root of 643297368 is about 25363.3075130197. The cubic root of 643297368 is about 863.2513340557.

The spelling of 643297368 in words is "six hundred forty-three million, two hundred ninety-seven thousand, three hundred sixty-eight".