208000138 has 4 divisors (see below), whose sum is σ = 312000210. Its totient is φ = 104000068.

The previous prime is 208000103. The next prime is 208000139. The reversal of 208000138 is 831000802.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 831000802 = 2 ⋅415500401.

It can be written as a sum of positive squares in only one way, i.e., 126405049 + 81595089 = 11243^2 + 9033^2 .

It is a Smith number, since the sum of its digits (22) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (208000139) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 52000033 + ... + 52000036.

Almost surely, 2^208000138 is an apocalyptic number.

208000138 is a deficient number, since it is larger than the sum of its proper divisors (104000072).

208000138 is a wasteful number, since it uses less digits than its factorization.

208000138 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 104000071.

The product of its (nonzero) digits is 384, while the sum is 22.

The square root of 208000138 is about 14422.2098861444. The cubic root of 208000138 is about 592.4993447149.

The spelling of 208000138 in words is "two hundred eight million, one hundred thirty-eight", and thus it is an aban number.