208138647 has 16 divisors (see below), whose sum is σ = 281387520. Its totient is φ = 136836672.

The previous prime is 208138627. The next prime is 208138663. The reversal of 208138647 is 746831802.

It is not a de Polignac number, because 208138647 - 2⁶ = 208138583 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (208138627) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 75363 + ... + 78075.

It is an arithmetic number, because the mean of its divisors is an integer number (17586720).

Almost surely, 2^208138647 is an apocalyptic number.

208138647 is a deficient number, since it is larger than the sum of its proper divisors (73248873).

208138647 is a wasteful number, since it uses less digits than its factorization.

208138647 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3062.

The product of its (nonzero) digits is 64512, while the sum is 39.

The square root of 208138647 is about 14427.0110209981. The cubic root of 208138647 is about 592.6308322595.

The spelling of 208138647 in words is "two hundred eight million, one hundred thirty-eight thousand, six hundred forty-seven".