138203520 has 384 divisors, whose sum is σ = 556748640. Its totient is φ = 28901376.

The previous prime is 138203519. The next prime is 138203521. The reversal of 138203520 is 25302831.

It is an interprime number because it is at equal distance from previous prime (138203519) and next prime (138203521).

It is a tau number, because it is divible by the number of its divisors (384).

It is a super-3 number, since 3×138203520³ (a number of 25 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138203521) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 1222984 + ... + 1223096.

Almost surely, 2^138203520 is an apocalyptic number.

138203520 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 138203520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (278374320).

138203520 is an abundant number, since it is smaller than the sum of its proper divisors (418545120).

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

138203520 is a wasteful number, since it uses less digits than its factorization.

138203520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 162 (or 143 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 24.

The square root of 138203520 is about 11755.9993194964. Note that the first 3 decimals coincide. The cubic root of 138203520 is about 517.0188390962.

The spelling of 138203520 in words is "one hundred thirty-eight million, two hundred three thousand, five hundred twenty".