138208068 has 18 divisors (see below), whose sum is σ = 349359374. Its totient is φ = 46069344.

The previous prime is 138208067. The next prime is 138208073. The reversal of 138208068 is 860802831.

It can be written as a sum of positive squares in only one way, i.e., 98366724 + 39841344 = 9918^2 + 6312^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is a Harshad number since it is a multiple of its sum of digits (36), and also a Moran number because the ratio is a prime number: 3839113 = 138208068 / (1 + 3 + 8 + 2 + 0 + 8 + 0 + 6 + 8).

It is not an unprimeable number, because it can be changed into a prime (138208067) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1919521 + ... + 1919592.

Almost surely, 2^138208068 is an apocalyptic number.

138208068 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

138208068 is an abundant number, since it is smaller than the sum of its proper divisors (211151306).

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

138208068 is a wasteful number, since it uses less digits than its factorization.

138208068 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3839123 (or 3839118 counting only the distinct ones).

The product of its (nonzero) digits is 18432, while the sum is 36.

The square root of 138208068 is about 11756.1927510568. The cubic root of 138208068 is about 517.0245103842.

The spelling of 138208068 in words is "one hundred thirty-eight million, two hundred eight thousand, sixty-eight".