138555750 has 64 divisors (see below), whose sum is σ = 355253184. Its totient is φ = 35942400.

The previous prime is 138555743. The next prime is 138555757. The reversal of 138555750 is 57555831.

It is an interprime number because it is at equal distance from previous prime (138555743) and next prime (138555757).

It is a junction number, because it is equal to n+sod(n) for n = 138555699 and 138555708.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138555757) 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, 25254 + ... + 30246.

It is an arithmetic number, because the mean of its divisors is an integer number (5550831).

Almost surely, 2^138555750 is an apocalyptic number.

138555750 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 138555750, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (177626592).

138555750 is an abundant number, since it is smaller than the sum of its proper divisors (216697434).

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

138555750 is a wasteful number, since it uses less digits than its factorization.

138555750 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5050 (or 5040 counting only the distinct ones).

The product of its (nonzero) digits is 105000, while the sum is 39.

The square root of 138555750 is about 11770.9706481666. The cubic root of 138555750 is about 517.4576968384.

The spelling of 138555750 in words is "one hundred thirty-eight million, five hundred fifty-five thousand, seven hundred fifty".