138524940 has 72 divisors (see below), whose sum is σ = 424962720. Its totient is φ = 36520704.

The previous prime is 138524923. The next prime is 138524941. The reversal of 138524940 is 49425831.

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

It is a junction number, because it is equal to n+sod(n) for n = 138524895 and 138524904.

It is not an unprimeable number, because it can be changed into a prime (138524941) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 11697 + ... + 20343.

It is an arithmetic number, because the mean of its divisors is an integer number (5902260).

Almost surely, 2^138524940 is an apocalyptic number.

138524940 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 138524940, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (212481360).

138524940 is an abundant number, since it is smaller than the sum of its proper divisors (286437780).

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

138524940 is a wasteful number, since it uses less digits than its factorization.

138524940 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8751 (or 8746 counting only the distinct ones).

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

The square root of 138524940 is about 11769.6618473090. The cubic root of 138524940 is about 517.4193391051.

The spelling of 138524940 in words is "one hundred thirty-eight million, five hundred twenty-four thousand, nine hundred forty".