639036 has 48 divisors (see below), whose sum is σ = 1701280. Its totient is φ = 207360.

The previous prime is 639011. The next prime is 639043. The reversal of 639036 is 630936.

It is a Harshad number since it is a multiple of its sum of digits (27).

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 639036.

It is an unprimeable number.

639036 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6540 + ... + 6636.

2⁶³⁹⁰³⁶ 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 639036, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (850640).

639036 is an abundant number, since it is smaller than the sum of its proper divisors (1062244).

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

639036 is a wasteful number, since it uses less digits than its factorization.

639036 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 171 (or 163 counting only the distinct ones).

The product of its (nonzero) digits is 2916, while the sum is 27.

The square root of 639036 is about 799.3972729501. The cubic root of 639036 is about 86.1340976288.

Subtracting from 639036 its reverse (630936), we obtain a square (8100 = 90²).

The spelling of 639036 in words is "six hundred thirty-nine thousand, thirty-six".