12471721 has 4 divisors (see below), whose sum is σ = 12527872. Its totient is φ = 12415572.

The previous prime is 12471707. The next prime is 12471751. The reversal of 12471721 is 12717421.

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, and also an emirpimes, since its reverse is a distinct semiprime: 12717421 = 41 ⋅310181.

It is a cyclic number.

It is not a de Polignac number, because 12471721 - 2⁵ = 12471689 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (12471751) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 27741 + ... + 28186.

It is an arithmetic number, because the mean of its divisors is an integer number (3131968).

Almost surely, 2^12471721 is an apocalyptic number.

It is an amenable number.

12471721 is a deficient number, since it is larger than the sum of its proper divisors (56151).

12471721 is an equidigital number, since it uses as much as digits as its factorization.

12471721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 56150.

The product of its digits is 784, while the sum is 25.

The square root of 12471721 is about 3531.5323869391. The cubic root of 12471721 is about 231.9042968821.

The spelling of 12471721 in words is "twelve million, four hundred seventy-one thousand, seven hundred twenty-one".