639711072 has 432 divisors, whose sum is σ = 2493992592. Its totient is φ = 152893440.

The previous prime is 639711001. The next prime is 639711103. The reversal of 639711072 is 270117936.

It is a happy number.

639711072 is a `hidden beast` number, since 639 + 7 + 1 + 10 + 7 + 2 = 666.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 2017858 + ... + 2018174.

It is an arithmetic number, because the mean of its divisors is an integer number (5773131).

Almost surely, 2^639711072 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 639711072, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1246996296).

639711072 is an abundant number, since it is smaller than the sum of its proper divisors (1854281520).

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

639711072 is a wasteful number, since it uses less digits than its factorization.

639711072 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 371 (or 353 counting only the distinct ones).

The product of its (nonzero) digits is 15876, while the sum is 36.

The square root of 639711072 is about 25292.5101957081. The cubic root of 639711072 is about 861.6441738873.

The spelling of 639711072 in words is "six hundred thirty-nine million, seven hundred eleven thousand, seventy-two".