1221455216441 has 2 divisors, whose sum is σ = 1221455216442. Its totient is φ = 1221455216440.

The previous prime is 1221455216419. The next prime is 1221455216453. The reversal of 1221455216441 is 1446125541221.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1205680861225 + 15774355216 = 1098035^2 + 125596^2 .

It is a cyclic number.

It is not a de Polignac number, because 1221455216441 - 2²² = 1221451022137 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1221455216395 and 1221455216404.

It is not a weakly prime, because it can be changed into another prime (1221455216411) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610727608220 + 610727608221.

It is an arithmetic number, because the mean of its divisors is an integer number (610727608221).

Almost surely, 2^{1221455216441} is an apocalyptic number.

It is an amenable number.

1221455216441 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221455216441 is an equidigital number, since it uses as much as digits as its factorization.

1221455216441 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 76800, while the sum is 38.

The spelling of 1221455216441 in words is "one trillion, two hundred twenty-one billion, four hundred fifty-five million, two hundred sixteen thousand, four hundred forty-one".