639846 has 48 divisors (see below), whose sum is σ = 1547280. Its totient is φ = 195840.

The previous prime is 639839. The next prime is 639851. The reversal of 639846 is 648936.

639846 = T₈₃ + T₈₄ + ... + T₁₆₃.

639846 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 639846.

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 639846.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 15586 + ... + 15626.

It is an arithmetic number, because the mean of its divisors is an integer number (32235).

2⁶³⁹⁸⁴⁶ is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 639846, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (773640).

639846 is an abundant number, since it is smaller than the sum of its proper divisors (907434).

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

639846 is a wasteful number, since it uses less digits than its factorization.

639846 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 86 (or 63 counting only the distinct ones).

The product of its digits is 31104, while the sum is 36.

The square root of 639846 is about 799.9037442093. The cubic root of 639846 is about 86.1704749022.

It can be divided in two parts, 639 and 846, that added together give a triangular number (1485 = T₅₄).

The spelling of 639846 in words is "six hundred thirty-nine thousand, eight hundred forty-six".