138589440 has 288 divisors, whose sum is σ = 513910656. Its totient is φ = 31457280.

The previous prime is 138589427. The next prime is 138589441. The reversal of 138589440 is 44985831.

It is a junction number, because it is equal to n+sod(n) for n = 138589392 and 138589401.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138589441) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 717984 + ... + 718176.

It is an arithmetic number, because the mean of its divisors is an integer number (1784412).

Almost surely, 2^138589440 is an apocalyptic number.

138589440 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 138589440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (256955328).

138589440 is an abundant number, since it is smaller than the sum of its proper divisors (375321216).

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

138589440 is a wasteful number, since it uses less digits than its factorization.

138589440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 245 (or 231 counting only the distinct ones).

The product of its (nonzero) digits is 138240, while the sum is 42.

The square root of 138589440 is about 11772.4016241377. The cubic root of 138589440 is about 517.4996335968.

The spelling of 138589440 in words is "one hundred thirty-eight million, five hundred eighty-nine thousand, four hundred forty".