138124728 has 240 divisors, whose sum is σ = 471912480. Its totient is φ = 36352512.

The previous prime is 138124703. The next prime is 138124739. The reversal of 138124728 is 827421831.

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

It is a nude number because it is divisible by every one of its digits.

It is a junction number, because it is equal to n+sod(n) for n = 138124692 and 138124701.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 59 ways as a sum of consecutive naturals, for example, 2938801 + ... + 2938847.

It is an arithmetic number, because the mean of its divisors is an integer number (1966302).

Almost surely, 2^138124728 is an apocalyptic number.

138124728 is a gapful number since it is divisible by the number (18) 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 138124728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (235956240).

138124728 is an abundant number, since it is smaller than the sum of its proper divisors (333787752).

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

138124728 is a wasteful number, since it uses less digits than its factorization.

138124728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 104 (or 76 counting only the distinct ones).

The product of its digits is 21504, while the sum is 36.

The square root of 138124728 is about 11752.6477016883. The cubic root of 138124728 is about 516.9205668949.

The spelling of 138124728 in words is "one hundred thirty-eight million, one hundred twenty-four thousand, seven hundred twenty-eight".