244520021 has 2 divisors, whose sum is σ = 244520022. Its totient is φ = 244520020.

The previous prime is 244520011. The next prime is 244520039. The reversal of 244520021 is 120025442.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 153412996 + 91107025 = 12386^2 + 9545^2 .

It is a cyclic number.

It is not a de Polignac number, because 244520021 - 2¹⁸ = 244257877 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 244519975 and 244520002.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (244520011) 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, 122260010 + 122260011.

It is an arithmetic number, because the mean of its divisors is an integer number (122260011).

Almost surely, 2^244520021 is an apocalyptic number.

It is an amenable number.

244520021 is a deficient number, since it is larger than the sum of its proper divisors (1).

244520021 is an equidigital number, since it uses as much as digits as its factorization.

244520021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 640, while the sum is 20.

The square root of 244520021 is about 15637.1359589920. The cubic root of 244520021 is about 625.3235836942.

Adding to 244520021 its reverse (120025442), we get a palindrome (364545463).

The spelling of 244520021 in words is "two hundred forty-four million, five hundred twenty thousand, twenty-one".