12009840 has 80 divisors (see below), whose sum is σ = 37580928. Its totient is φ = 3172608.

The previous prime is 12009827. The next prime is 12009859. The reversal of 12009840 is 4890021.

It is a tau number, because it is divible by the number of its divisors (80).

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a self number, because there is not a number n which added to its sum of digits gives 12009840.

It is a congruent number.

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 15 ways as a sum of consecutive naturals, for example, 38967 + ... + 39273.

Almost surely, 2^12009840 is an apocalyptic number.

12009840 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 12009840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (18790464).

12009840 is an abundant number, since it is smaller than the sum of its proper divisors (25571088).

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

12009840 is a wasteful number, since it uses less digits than its factorization.

12009840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 486 (or 480 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 24.

The square root of 12009840 is about 3465.5216057615. The cubic root of 12009840 is about 229.0054091258.

Adding to 12009840 its reverse (4890021), we get a palindrome (16899861).

The spelling of 12009840 in words is "twelve million, nine thousand, eight hundred forty".