191208138 has 16 divisors (see below), whose sum is σ = 417181536. Its totient is φ = 57941840.

The previous prime is 191208089. The next prime is 191208139. The reversal of 191208138 is 831802191.

191208138 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a junction number, because it is equal to n+sod(n) for n = 191208099 and 191208108.

It is not an unprimeable number, because it can be changed into a prime (191208139) 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, 1448481 + ... + 1448612.

It is an arithmetic number, because the mean of its divisors is an integer number (26073846).

Almost surely, 2^191208138 is an apocalyptic number.

191208138 is an abundant number, since it is smaller than the sum of its proper divisors (225973398).

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

191208138 is a wasteful number, since it uses less digits than its factorization.

191208138 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2897109.

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

The square root of 191208138 is about 13827.8030793037. The cubic root of 191208138 is about 576.1056362486.

The spelling of 191208138 in words is "one hundred ninety-one million, two hundred eight thousand, one hundred thirty-eight".