12321440 has 48 divisors (see below), whose sum is σ = 29679048. Its totient is φ = 4832256.

The previous prime is 12321437. The next prime is 12321461. The reversal of 12321440 is 4412321.

It can be written as a sum of positive squares in 4 ways, for example, as 12306064 + 15376 = 3508^2 + 124^2 .

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, 7754 + ... + 9206.

Almost surely, 2^12321440 is an apocalyptic number.

12321440 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 12321440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (14839524).

12321440 is an abundant number, since it is smaller than the sum of its proper divisors (17357608).

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

12321440 is a wasteful number, since it uses less digits than its factorization.

12321440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1521 (or 1513 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 17.

The square root of 12321440 is about 3510.1908780008. The cubic root of 12321440 is about 230.9690681520.

Adding to 12321440 its reverse (4412321), we get a palindrome (16733761).

The spelling of 12321440 in words is "twelve million, three hundred twenty-one thousand, four hundred forty".