643272064 has 32 divisors (see below), whose sum is σ = 1295940600. Its totient is φ = 318016512.

The previous prime is 643272053. The next prime is 643272067. The reversal of 643272064 is 460272346.

It is a tau number, because it is divible by the number of its divisors (32).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (643272067) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16842 + ... + 39625.

Almost surely, 2^643272064 is an apocalyptic number.

643272064 is a gapful number since it is divisible by the number (64) formed by its first and last digit.

It is an amenable number.

643272064 is an abundant number, since it is smaller than the sum of its proper divisors (652668536).

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

643272064 is an equidigital number, since it uses as much as digits as its factorization.

643272064 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 56570 (or 56558 counting only the distinct ones).

The product of its (nonzero) digits is 48384, while the sum is 34.

The square root of 643272064 is about 25362.8086772739. The cubic root of 643272064 is about 863.2400152892.

The spelling of 643272064 in words is "six hundred forty-three million, two hundred seventy-two thousand, sixty-four".