12040721 has 24 divisors (see below), whose sum is σ = 15513120. Its totient is φ = 9240000.

The previous prime is 12040711. The next prime is 12040723. The reversal of 12040721 is 12704021.

It is a de Polignac number, because none of the positive numbers 2^k-12040721 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 12040721.

It is not an unprimeable number, because it can be changed into a prime (12040723) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 47846 + ... + 48096.

It is an arithmetic number, because the mean of its divisors is an integer number (646380).

Almost surely, 2^12040721 is an apocalyptic number.

12040721 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

12040721 is a deficient number, since it is larger than the sum of its proper divisors (3472399).

12040721 is a wasteful number, since it uses less digits than its factorization.

12040721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 365 (or 358 counting only the distinct ones).

The product of its (nonzero) digits is 112, while the sum is 17.

The square root of 12040721 is about 3469.9742073969. The cubic root of 12040721 is about 229.2015222942.

Adding to 12040721 its reverse (12704021), we get a palindrome (24744742).

The spelling of 12040721 in words is "twelve million, forty thousand, seven hundred twenty-one".