138218240 has 72 divisors (see below), whose sum is σ = 335322288. Its totient is φ = 54579200.

The previous prime is 138218239. The next prime is 138218281. The reversal of 138218240 is 42812831.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 105590 + ... + 106890.

It is an arithmetic number, because the mean of its divisors is an integer number (4657254).

Almost surely, 2^138218240 is an apocalyptic number.

138218240 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 138218240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (167661144).

138218240 is an abundant number, since it is smaller than the sum of its proper divisors (197104048).

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

138218240 is an equidigital number, since it uses as much as digits as its factorization.

138218240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1405 (or 1391 counting only the distinct ones).

The product of its (nonzero) digits is 3072, while the sum is 29.

The square root of 138218240 is about 11756.6253661499. The cubic root of 138218240 is about 517.0371942657.

The spelling of 138218240 in words is "one hundred thirty-eight million, two hundred eighteen thousand, two hundred forty".