639198 has 64 divisors (see below), whose sum is σ = 1728000. Its totient is φ = 171072.

The previous prime is 639181. The next prime is 639211. The reversal of 639198 is 891936.

639198 is a `hidden beast` number, since 639 + 19 + 8 = 666.

639198 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 congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 639198.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 7138 + ... + 7226.

It is an arithmetic number, because the mean of its divisors is an integer number (27000).

2⁶³⁹¹⁹⁸ is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 639198, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (864000).

639198 is an abundant number, since it is smaller than the sum of its proper divisors (1088802).

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

639198 is a wasteful number, since it uses less digits than its factorization.

639198 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 126 (or 120 counting only the distinct ones).

The product of its digits is 11664, while the sum is 36.

The square root of 639198 is about 799.4985928693. The cubic root of 639198 is about 86.1413755416.

It can be divided in two parts, 63 and 9198, that added together give a cube (9261 = 21³).

The spelling of 639198 in words is "six hundred thirty-nine thousand, one hundred ninety-eight".