643570720 has 96 divisors (see below), whose sum is σ = 1644774768. Its totient is φ = 236556288.

The previous prime is 643570709. The next prime is 643570747. The reversal of 643570720 is 27075346.

It is a happy number.

It can be written as a sum of positive squares in 8 ways, for example, as 1860496 + 641710224 = 1364^2 + 25332^2 .

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, 575602 + ... + 576718.

Almost surely, 2^643570720 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 643570720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (822387384).

643570720 is an abundant number, since it is smaller than the sum of its proper divisors (1001204048).

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

643570720 is a wasteful number, since it uses less digits than its factorization.

643570720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1422 (or 1414 counting only the distinct ones).

The product of its (nonzero) digits is 35280, while the sum is 34.

The square root of 643570720 is about 25368.6956700576. The cubic root of 643570720 is about 863.3735885915.

The spelling of 643570720 in words is "six hundred forty-three million, five hundred seventy thousand, seven hundred twenty".