639528372 has 336 divisors, whose sum is σ = 2159418240. Its totient is φ = 161243136.

The previous prime is 639528371. The next prime is 639528403. The reversal of 639528372 is 273825936.

639528372 is a `hidden beast` number, since 639 + 5 + 2 + 8 + 3 + 7 + 2 = 666.

Its product of digits (544320) is a multiple of the sum of its prime factors (162).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (639528371) by changing a digit.

It is a polite number, since it can be written in 111 ways as a sum of consecutive naturals, for example, 6593028 + ... + 6593124.

It is an arithmetic number, because the mean of its divisors is an integer number (6426840).

Almost surely, 2^639528372 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 639528372, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1079709120).

639528372 is an abundant number, since it is smaller than the sum of its proper divisors (1519889868).

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

639528372 is a wasteful number, since it uses less digits than its factorization.

639528372 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 162 (or 145 counting only the distinct ones).

The product of its digits is 544320, while the sum is 45.

The square root of 639528372 is about 25288.8981966396. The cubic root of 639528372 is about 861.5621382172.

The spelling of 639528372 in words is "six hundred thirty-nine million, five hundred twenty-eight thousand, three hundred seventy-two".