208139100 has 144 divisors (see below), whose sum is σ = 657374592. Its totient is φ = 50538240.

The previous prime is 208139093. The next prime is 208139117. The reversal of 208139100 is 1931802.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 323379 + ... + 324021.

Almost surely, 2^208139100 is an apocalyptic number.

208139100 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 208139100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (328687296).

208139100 is an abundant number, since it is smaller than the sum of its proper divisors (449235492).

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

208139100 is a wasteful number, since it uses less digits than its factorization.

208139100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 756 (or 749 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 24.

The square root of 208139100 is about 14427.0267207072. The cubic root of 208139100 is about 592.6312621997.

The spelling of 208139100 in words is "two hundred eight million, one hundred thirty-nine thousand, one hundred".