208191138 has 16 divisors (see below), whose sum is σ = 416888640. Its totient is φ = 69312656.

The previous prime is 208191131. The next prime is 208191157. The reversal of 208191138 is 831191802.

208191138 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 junction number, because it is equal to n+sod(n) for n = 208191099 and 208191108.

It is not an unprimeable number, because it can be changed into a prime (208191131) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 15645 + ... + 25712.

It is an arithmetic number, because the mean of its divisors is an integer number (26055540).

Almost surely, 2^208191138 is an apocalyptic number.

208191138 is an abundant number, since it is smaller than the sum of its proper divisors (208697502).

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

208191138 is a wasteful number, since it uses less digits than its factorization.

208191138 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42201.

The product of its (nonzero) digits is 3456, while the sum is 33.

The square root of 208191138 is about 14428.8300981057. The cubic root of 208191138 is about 592.6806470837.

The spelling of 208191138 in words is "two hundred eight million, one hundred ninety-one thousand, one hundred thirty-eight".