12207721 has 2 divisors, whose sum is σ = 12207722. Its totient is φ = 12207720.

The previous prime is 12207703. The next prime is 12207731. The reversal of 12207721 is 12770221.

12207721 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 7645225 + 4562496 = 2765^2 + 2136^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-12207721 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 12207692 and 12207701.

It is not a weakly prime, because it can be changed into another prime (12207731) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6103860 + 6103861.

It is an arithmetic number, because the mean of its divisors is an integer number (6103861).

Almost surely, 2^12207721 is an apocalyptic number.

It is an amenable number.

12207721 is a deficient number, since it is larger than the sum of its proper divisors (1).

12207721 is an equidigital number, since it uses as much as digits as its factorization.

12207721 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 392, while the sum is 22.

The square root of 12207721 is about 3493.9549224339. The cubic root of 12207721 is about 230.2563053270.

Adding to 12207721 its reverse (12770221), we get a palindrome (24977942).

Subtracting 12207721 from its reverse (12770221), we obtain a square (562500 = 750²).

The spelling of 12207721 in words is "twelve million, two hundred seven thousand, seven hundred twenty-one".