1221021304309 has 2 divisors, whose sum is σ = 1221021304310. Its totient is φ = 1221021304308.

The previous prime is 1221021304241. The next prime is 1221021304357. The reversal of 1221021304309 is 9034031201221.

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., 1013908024900 + 207113279409 = 1006930^2 + 455097^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1221021304309 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1221021304369) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610510652154 + 610510652155.

It is an arithmetic number, because the mean of its divisors is an integer number (610510652155).

Almost surely, 2^{1221021304309} is an apocalyptic number.

It is an amenable number.

1221021304309 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221021304309 is an equidigital number, since it uses as much as digits as its factorization.

1221021304309 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2592, while the sum is 28.

The spelling of 1221021304309 in words is "one trillion, two hundred twenty-one billion, twenty-one million, three hundred four thousand, three hundred nine".