1244224021 has 2 divisors, whose sum is σ = 1244224022. Its totient is φ = 1244224020.

The previous prime is 1244224019. The next prime is 1244224039. The reversal of 1244224021 is 1204224421.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1242562500 + 1661521 = 35250^2 + 1289^2 .

It is a cyclic number.

It is not a de Polignac number, because 1244224021 - 2¹ = 1244224019 is a prime.

Together with 1244224019, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 1244223983 and 1244224001.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1244224061) 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 as a sum of consecutive naturals, namely, 622112010 + 622112011.

It is an arithmetic number, because the mean of its divisors is an integer number (622112011).

Almost surely, 2^1244224021 is an apocalyptic number.

It is an amenable number.

1244224021 is a deficient number, since it is larger than the sum of its proper divisors (1).

1244224021 is an equidigital number, since it uses as much as digits as its factorization.

1244224021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1024, while the sum is 22.

The square root of 1244224021 is about 35273.5598005078. The cubic root of 1244224021 is about 1075.5555869034. Note that the first 4 decimals are identical.

Adding to 1244224021 its reverse (1204224421), we get a palindrome (2448448442).

It can be divided in two parts, 12442 and 24021, that added together give a palindrome (36463).

The spelling of 1244224021 in words is "one billion, two hundred forty-four million, two hundred twenty-four thousand, twenty-one".