1224240221 has 2 divisors, whose sum is σ = 1224240222. Its totient is φ = 1224240220.

The previous prime is 1224240203. The next prime is 1224240247. The reversal of 1224240221 is 1220424221.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 757075225 + 467164996 = 27515^2 + 21614^2 .

It is a cyclic number.

It is not a de Polignac number, because 1224240221 - 2¹⁴ = 1224223837 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1224240193 and 1224240202.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1224240271) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 612120110 + 612120111.

It is an arithmetic number, because the mean of its divisors is an integer number (612120111).

Almost surely, 2^1224240221 is an apocalyptic number.

It is an amenable number.

1224240221 is a deficient number, since it is larger than the sum of its proper divisors (1).

1224240221 is an equidigital number, since it uses as much as digits as its factorization.

1224240221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 512, while the sum is 20.

The square root of 1224240221 is about 34989.1443307778. The cubic root of 1224240221 is about 1069.7662228377.

Adding to 1224240221 its reverse (1220424221), we get a palindrome (2444664442).

The spelling of 1224240221 in words is "one billion, two hundred twenty-four million, two hundred forty thousand, two hundred twenty-one".