138172320 has 432 divisors, whose sum is σ = 567291816. Its totient is φ = 30412800.

The previous prime is 138172273. The next prime is 138172357. The reversal of 138172320 is 23271831.

It can be written as a sum of positive squares in 4 ways, for example, as 45319824 + 92852496 = 6732^2 + 9636^2 .

It is a super-3 number, since 3×138172320³ (a number of 25 digits) contains 333 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 2265090 + ... + 2265150.

Almost surely, 2^138172320 is an apocalyptic number.

138172320 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 138172320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (283645908).

138172320 is an abundant number, since it is smaller than the sum of its proper divisors (429119496).

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

138172320 is a wasteful number, since it uses less digits than its factorization.

138172320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 117 (or 95 counting only the distinct ones).

The product of its (nonzero) digits is 2016, while the sum is 27.

The square root of 138172320 is about 11754.6722625516. The cubic root of 138172320 is about 516.9799298079.

The spelling of 138172320 in words is "one hundred thirty-eight million, one hundred seventy-two thousand, three hundred twenty".