138685320 has 288 divisors, whose sum is σ = 505739520. Its totient is φ = 32901120.

The previous prime is 138685319. The next prime is 138685321. The reversal of 138685320 is 23586831.

138685320 = T₁₀₄ + T₁₀₅ + ... + T₉₄₀.

It is an interprime number because it is at equal distance from previous prime (138685319) and next prime (138685321).

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 (138685321) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 3225219 + ... + 3225261.

It is an arithmetic number, because the mean of its divisors is an integer number (1756040).

Almost surely, 2^138685320 is an apocalyptic number.

138685320 is a gapful number since it is divisible by the number (10) 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 138685320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (252869760).

138685320 is an abundant number, since it is smaller than the sum of its proper divisors (367054200).

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

138685320 is a wasteful number, since it uses less digits than its factorization.

138685320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 125 (or 101 counting only the distinct ones).

The product of its (nonzero) digits is 34560, while the sum is 36.

The square root of 138685320 is about 11776.4731562552. The cubic root of 138685320 is about 517.6189462633.

The spelling of 138685320 in words is "one hundred thirty-eight million, six hundred eighty-five thousand, three hundred twenty".