1225243544221 has 2 divisors, whose sum is σ = 1225243544222. Its totient is φ = 1225243544220.

The previous prime is 1225243544177. The next prime is 1225243544243. The reversal of 1225243544221 is 1224453425221.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1009934552025 + 215308992196 = 1004955^2 + 464014^2 .

It is a cyclic number.

It is not a de Polignac number, because 1225243544221 - 2¹⁹ = 1225243019933 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1225243544321) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 612621772110 + 612621772111.

It is an arithmetic number, because the mean of its divisors is an integer number (612621772111).

Almost surely, 2^{1225243544221} is an apocalyptic number.

It is an amenable number.

1225243544221 is a deficient number, since it is larger than the sum of its proper divisors (1).

1225243544221 is an equidigital number, since it uses as much as digits as its factorization.

1225243544221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 153600, while the sum is 37.

Adding to 1225243544221 its reverse (1224453425221), we get a palindrome (2449696969442).

The spelling of 1225243544221 in words is "one trillion, two hundred twenty-five billion, two hundred forty-three million, five hundred forty-four thousand, two hundred twenty-one".