138755540 has 72 divisors (see below), whose sum is σ = 366084096. Its totient is φ = 43243200.

The previous prime is 138755497. The next prime is 138755549. The reversal of 138755540 is 45557831.

It is a junction number, because it is equal to n+sod(n) for n = 138755494 and 138755503.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138755549) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 12845 + ... + 21035.

Almost surely, 2^138755540 is an apocalyptic number.

138755540 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 138755540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (183042048).

138755540 is an abundant number, since it is smaller than the sum of its proper divisors (227328556).

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

138755540 is a wasteful number, since it uses less digits than its factorization.

138755540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8229 (or 8216 counting only the distinct ones).

The product of its (nonzero) digits is 84000, while the sum is 38.

The square root of 138755540 is about 11779.4541469459. The cubic root of 138755540 is about 517.7062928540.

The spelling of 138755540 in words is "one hundred thirty-eight million, seven hundred fifty-five thousand, five hundred forty".