12591721 has 8 divisors (see below), whose sum is σ = 12860640. Its totient is φ = 12324768.

The previous prime is 12591707. The next prime is 12591727. The reversal of 12591721 is 12719521.

12591721 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 12591721 - 2⁹ = 12591209 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 12591721.

It is not an unprimeable number, because it can be changed into a prime (12591727) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 26730 + ... + 27196.

It is an arithmetic number, because the mean of its divisors is an integer number (1607580).

Almost surely, 2^12591721 is an apocalyptic number.

It is an amenable number.

12591721 is a deficient number, since it is larger than the sum of its proper divisors (268919).

12591721 is an equidigital number, since it uses as much as digits as its factorization.

12591721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 983.

The product of its digits is 1260, while the sum is 28.

The square root of 12591721 is about 3548.4815062221. The cubic root of 12591721 is about 232.6457004814.

The spelling of 12591721 in words is "twelve million, five hundred ninety-one thousand, seven hundred twenty-one".