12405440 has 28 divisors (see below), whose sum is σ = 29541216. Its totient is φ = 4962048.

The previous prime is 12405433. The next prime is 12405467. The reversal of 12405440 is 4450421.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 19064 + ... + 19703.

Almost surely, 2^12405440 is an apocalyptic number.

12405440 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

12405440 is an abundant number, since it is smaller than the sum of its proper divisors (17135776).

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

12405440 is an equidigital number, since it uses as much as digits as its factorization.

12405440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38784 (or 38774 counting only the distinct ones).

The product of its (nonzero) digits is 640, while the sum is 20.

The square root of 12405440 is about 3522.1357157270. The cubic root of 12405440 is about 231.4927482579.

Adding to 12405440 its reverse (4450421), we get a palindrome (16855861).

The spelling of 12405440 in words is "twelve million, four hundred five thousand, four hundred forty".