138506208 has 48 divisors (see below), whose sum is σ = 384970320. Its totient is φ = 43452416.

The previous prime is 138506201. The next prime is 138506243. The reversal of 138506208 is 802605831.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (48).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138506201) 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, 40803 + ... + 44066.

It is an arithmetic number, because the mean of its divisors is an integer number (8020215).

Almost surely, 2^138506208 is an apocalyptic number.

It is an amenable number.

138506208 is an abundant number, since it is smaller than the sum of its proper divisors (246464112).

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

138506208 is a wasteful number, since it uses less digits than its factorization.

138506208 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 84899 (or 84891 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 33.

The square root of 138506208 is about 11768.8660456307. The cubic root of 138506208 is about 517.3960154207.

The spelling of 138506208 in words is "one hundred thirty-eight million, five hundred six thousand, two hundred eight".