643360320 has 140 divisors (see below), whose sum is σ = 2288638044. Its totient is φ = 171555840.

The previous prime is 643360309. The next prime is 643360321. The reversal of 643360320 is 23063346.

643360320 is a `hidden beast` number, since 6 + 4 + 33 + 603 + 20 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 151585344 + 491774976 = 12312^2 + 22176^2 .

It is a hoax number, since the sum of its digits (27) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (643360321) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 13510 + ... + 38330.

Almost surely, 2^643360320 is an apocalyptic number.

643360320 is a gapful number since it is divisible by the number (60) 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 643360320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1144319022).

643360320 is an abundant number, since it is smaller than the sum of its proper divisors (1645277724).

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

643360320 is a wasteful number, since it uses less digits than its factorization.

643360320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24850 (or 24831 counting only the distinct ones).

The product of its (nonzero) digits is 7776, while the sum is 27.

The square root of 643360320 is about 25364.5484879980. The cubic root of 643360320 is about 863.2794919125.

The spelling of 643360320 in words is "six hundred forty-three million, three hundred sixty thousand, three hundred twenty".