12090721 has 4 divisors (see below), whose sum is σ = 12170944. Its totient is φ = 12010500.

The previous prime is 12090719. The next prime is 12090763. The reversal of 12090721 is 12709021.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 12090721 - 2¹ = 12090719 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 12090692 and 12090701.

It is not an unprimeable number, because it can be changed into a prime (12099721) 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 3 ways as a sum of consecutive naturals, for example, 39885 + ... + 40186.

It is an arithmetic number, because the mean of its divisors is an integer number (3042736).

Almost surely, 2^12090721 is an apocalyptic number.

It is an amenable number.

12090721 is a deficient number, since it is larger than the sum of its proper divisors (80223).

12090721 is an equidigital number, since it uses as much as digits as its factorization.

12090721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 80222.

The product of its (nonzero) digits is 252, while the sum is 22.

The square root of 12090721 is about 3477.1714079119. The cubic root of 12090721 is about 229.5183430136.

Adding to 12090721 its reverse (12709021), we get a palindrome (24799742).

The spelling of 12090721 in words is "twelve million, ninety thousand, seven hundred twenty-one".