643320456 has 64 divisors (see below), whose sum is σ = 1671321600. Its totient is φ = 206105088.

The previous prime is 643320439. The next prime is 643320493. The reversal of 643320456 is 654023346.

It is a super-2 number, since 2×643320456² = 827722418216095872, which contains 22 as substring.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 160185 + ... + 164151.

It is an arithmetic number, because the mean of its divisors is an integer number (26114400).

Almost surely, 2^643320456 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 643320456, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (835660800).

643320456 is an abundant number, since it is smaller than the sum of its proper divisors (1028001144).

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

643320456 is a wasteful number, since it uses less digits than its factorization.

643320456 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4238 (or 4234 counting only the distinct ones).

The product of its (nonzero) digits is 51840, while the sum is 33.

The square root of 643320456 is about 25363.7626546220. The cubic root of 643320456 is about 863.2616613214.

The spelling of 643320456 in words is "six hundred forty-three million, three hundred twenty thousand, four hundred fifty-six".