639545472 has 192 divisors, whose sum is σ = 1973088000. Its totient is φ = 198236160.

The previous prime is 639545471. The next prime is 639545503. The reversal of 639545472 is 274545936.

639545472 is a `hidden beast` number, since 6 + 39 + 545 + 4 + 72 = 666.

It is a tau number, because it is divible by the number of its divisors (192).

It is not an unprimeable number, because it can be changed into a prime (639545471) by changing a digit.

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 23 ways as a sum of consecutive naturals, for example, 1334929 + ... + 1335407.

It is an arithmetic number, because the mean of its divisors is an integer number (10276500).

Almost surely, 2^639545472 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 639545472, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (986544000).

639545472 is an abundant number, since it is smaller than the sum of its proper divisors (1333542528).

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

639545472 is a wasteful number, since it uses less digits than its factorization.

639545472 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 579 (or 564 counting only the distinct ones).

The product of its digits is 907200, while the sum is 45.

The square root of 639545472 is about 25289.2362874010. The cubic root of 639545472 is about 861.5698170953.

The spelling of 639545472 in words is "six hundred thirty-nine million, five hundred forty-five thousand, four hundred seventy-two".