639216 has 60 divisors (see below), whose sum is σ = 1876368. Its totient is φ = 202752.

The previous prime is 639211. The next prime is 639253. The reversal of 639216 is 612936.

It is a happy number.

639216 is a `hidden beast` number, since 639 + 21 + 6 = 666.

It is a nude number because it is divisible by every one of its digits.

It is an Ulam number.

It is a self number, because there is not a number n which added to its sum of digits gives 639216.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 639216.

It is not an unprimeable number, because it can be changed into a prime (639211) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3216 + ... + 3408.

2⁶³⁹²¹⁶ 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 639216, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (938184).

639216 is an abundant number, since it is smaller than the sum of its proper divisors (1237152).

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

639216 is a wasteful number, since it uses less digits than its factorization.

639216 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 230 (or 221 counting only the distinct ones).

The product of its digits is 1944, while the sum is 27.

The square root of 639216 is about 799.5098498455. The cubic root of 639216 is about 86.1421841227.

The spelling of 639216 in words is "six hundred thirty-nine thousand, two hundred sixteen".