138124840 has 64 divisors (see below), whose sum is σ = 366658560. Its totient is φ = 45826560.

The previous prime is 138124829. The next prime is 138124843. The reversal of 138124840 is 48421831.

It is a Harshad number since it is a multiple of its sum of digits (31).

It is not an unprimeable number, because it can be changed into a prime (138124843) 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 15 ways as a sum of consecutive naturals, for example, 724 + ... + 16636.

It is an arithmetic number, because the mean of its divisors is an integer number (5729040).

Almost surely, 2^138124840 is an apocalyptic number.

138124840 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 138124840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (183329280).

138124840 is an abundant number, since it is smaller than the sum of its proper divisors (228533720).

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

138124840 is a wasteful number, since it uses less digits than its factorization.

138124840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15962 (or 15958 counting only the distinct ones).

The product of its (nonzero) digits is 6144, while the sum is 31.

The square root of 138124840 is about 11752.6524665711. The cubic root of 138124840 is about 516.9207066118.

The spelling of 138124840 in words is "one hundred thirty-eight million, one hundred twenty-four thousand, eight hundred forty".