639345616 has 80 divisors (see below), whose sum is σ = 1530290944. Its totient is φ = 251983872.

The previous prime is 639345599. The next prime is 639345647. The reversal of 639345616 is 616543936.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 490021 + ... + 491323.

Almost surely, 2^639345616 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 639345616, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (765145472).

639345616 is an abundant number, since it is smaller than the sum of its proper divisors (890945328).

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

639345616 is a wasteful number, since it uses less digits than its factorization.

639345616 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1668 (or 1662 counting only the distinct ones).

The product of its digits is 349920, while the sum is 43.

The square root of 639345616 is about 25285.2845742341. The cubic root of 639345616 is about 861.4800617695.

The spelling of 639345616 in words is "six hundred thirty-nine million, three hundred forty-five thousand, six hundred sixteen".