12138240 has 144 divisors (see below), whose sum is σ = 40471200. Its totient is φ = 3096576.

The previous prime is 12138229. The next prime is 12138251. The reversal of 12138240 is 4283121.

It is an interprime number because it is at equal distance from previous prime (12138229) and next prime (12138251).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 111306 + ... + 111414.

It is an arithmetic number, because the mean of its divisors is an integer number (281050).

Almost surely, 2^12138240 is an apocalyptic number.

12138240 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 12138240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (20235600).

12138240 is an abundant number, since it is smaller than the sum of its proper divisors (28332960).

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

12138240 is a wasteful number, since it uses less digits than its factorization.

12138240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 162 (or 148 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 21.

The square root of 12138240 is about 3483.9977037880. The cubic root of 12138240 is about 229.8186345905.

It can be divided in two parts, 1213 and 8240, that added together give a triangular number (9453 = T₁₃₇).

The spelling of 12138240 in words is "twelve million, one hundred thirty-eight thousand, two hundred forty".