639800 has 48 divisors (see below), whose sum is σ = 1703760. Its totient is φ = 218880.

The previous prime is 639757. The next prime is 639833. The reversal of 639800 is 8936.

It is a happy number.

It is a nialpdrome in base 15.

It is a self number, because there is not a number n which added to its sum of digits gives 639800.

It is a congruent number.

It is an unprimeable number.

639800 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 11 ways as a sum of consecutive naturals, for example, 1172 + ... + 1628.

It is an arithmetic number, because the mean of its divisors is an integer number (35495).

2⁶³⁹⁸⁰⁰ 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 639800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (851880).

639800 is an abundant number, since it is smaller than the sum of its proper divisors (1063960).

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

639800 is a wasteful number, since it uses less digits than its factorization.

639800 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 480 (or 471 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 26.

The square root of 639800 is about 799.8749902328. The cubic root of 639800 is about 86.1684098548.

The spelling of 639800 in words is "six hundred thirty-nine thousand, eight hundred".