138018816 has 180 divisors, whose sum is σ = 444070242. Its totient is φ = 42467328.

The previous prime is 138018781. The next prime is 138018821. The reversal of 138018816 is 618810831.

It can be written as a sum of positive squares in only one way, i.e., 132710400 + 5308416 = 11520^2 + 2304^2 .

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

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 10616826 + ... + 10616838.

Almost surely, 2^138018816 is an apocalyptic number.

138018816 is a gapful number since it is divisible by the number (16) 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 138018816, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (222035121).

138018816 is an abundant number, since it is smaller than the sum of its proper divisors (306051426).

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

138018816 is an frugal number, since it uses more digits than its factorization.

138018816 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 59 (or 18 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 36.

The square root of 138018816 is about 11748.1409593178. The cubic root of 138018816 is about 516.7884107604.

The spelling of 138018816 in words is "one hundred thirty-eight million, eighteen thousand, eight hundred sixteen".