639616 has 32 divisors (see below), whose sum is σ = 1346400. Its totient is φ = 301824.

The previous prime is 639601. The next prime is 639631. The reversal of 639616 is 616936.

It is an interprime number because it is at equal distance from previous prime (639601) and next prime (639631).

It is a tau number, because it is divible by the number of its divisors (32).

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2301 + ... + 2563.

It is an arithmetic number, because the mean of its divisors is an integer number (42075).

2⁶³⁹⁶¹⁶ 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 639616, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (673200).

639616 is an abundant number, since it is smaller than the sum of its proper divisors (706784).

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

639616 is a wasteful number, since it uses less digits than its factorization.

639616 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 296 (or 284 counting only the distinct ones).

The product of its digits is 5832, while the sum is 31.

The square root of 639616 is about 799.7599639892. The cubic root of 639616 is about 86.1601486755.

The spelling of 639616 in words is "six hundred thirty-nine thousand, six hundred sixteen".