138815208 has 144 divisors (see below), whose sum is σ = 450035040. Its totient is φ = 39268800.

The previous prime is 138815203. The next prime is 138815227. The reversal of 138815208 is 802518831.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is not an unprimeable number, because it can be changed into a prime (138815203) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 1374358 + ... + 1374458.

Almost surely, 2^138815208 is an apocalyptic number.

138815208 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 138815208, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (225017520).

138815208 is an abundant number, since it is smaller than the sum of its proper divisors (311219832).

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

138815208 is an equidigital number, since it uses as much as digits as its factorization.

138815208 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 230 (or 113 counting only the distinct ones).

The product of its (nonzero) digits is 15360, while the sum is 36.

The square root of 138815208 is about 11781.9865897055. The cubic root of 138815208 is about 517.7804906656.

The spelling of 138815208 in words is "one hundred thirty-eight million, eight hundred fifteen thousand, two hundred eight".