7440243221 has 2 divisors, whose sum is σ = 7440243222. Its totient is φ = 7440243220.

The previous prime is 7440243211. The next prime is 7440243229. The reversal of 7440243221 is 1223420447.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 6728100625 + 712142596 = 82025^2 + 26686^2 .

It is an emirp because it is prime and its reverse (1223420447) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 7440243221 - 2³⁰ = 6366501397 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (7440243229) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3720121610 + 3720121611.

It is an arithmetic number, because the mean of its divisors is an integer number (3720121611).

Almost surely, 2^7440243221 is an apocalyptic number.

It is an amenable number.

7440243221 is a deficient number, since it is larger than the sum of its proper divisors (1).

7440243221 is an equidigital number, since it uses as much as digits as its factorization.

7440243221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 10752, while the sum is 29.

The square root of 7440243221 is about 86256.8444878434. The cubic root of 7440243221 is about 1952.2212882253.

Adding to 7440243221 its reverse (1223420447), we get a palindrome (8663663668).

The spelling of 7440243221 in words is "seven billion, four hundred forty million, two hundred forty-three thousand, two hundred twenty-one".