643465368 has 384 divisors, whose sum is σ = 2335132800. Its totient is φ = 155271168.

The previous prime is 643465367. The next prime is 643465397. The reversal of 643465368 is 863564346.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643465363) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 5903298 + ... + 5903406.

It is an arithmetic number, because the mean of its divisors is an integer number (6081075).

Almost surely, 2^643465368 is an apocalyptic number.

643465368 is a gapful number since it is divisible by the number (68) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 643465368, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1167566400).

643465368 is an abundant number, since it is smaller than the sum of its proper divisors (1691667432).

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

643465368 is a wasteful number, since it uses less digits than its factorization.

643465368 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 211 (or 204 counting only the distinct ones).

The product of its digits is 1244160, while the sum is 45.

The square root of 643465368 is about 25366.6191677172. The cubic root of 643465368 is about 863.3264748374.

The spelling of 643465368 in words is "six hundred forty-three million, four hundred sixty-five thousand, three hundred sixty-eight".