643372704 has 144 divisors (see below), whose sum is σ = 1981324800. Its totient is φ = 196858368.

The previous prime is 643372679. The next prime is 643372747. The reversal of 643372704 is 407273346.

It is a happy number.

643372704 is a `hidden beast` number, since 643 + 3 + 7 + 2 + 7 + 0 + 4 = 666.

It is a tau number, because it is divible by the number of its divisors (144).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 894457 + ... + 895175.

It is an arithmetic number, because the mean of its divisors is an integer number (13759200).

Almost surely, 2^643372704 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 643372704, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (990662400).

643372704 is an abundant number, since it is smaller than the sum of its proper divisors (1337952096).

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

643372704 is a wasteful number, since it uses less digits than its factorization.

643372704 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 987 (or 976 counting only the distinct ones).

The product of its (nonzero) digits is 84672, while the sum is 36.

The square root of 643372704 is about 25364.7926070764. The cubic root of 643372704 is about 863.2850309468.

The spelling of 643372704 in words is "six hundred forty-three million, three hundred seventy-two thousand, seven hundred four".