1221023021513 has 2 divisors, whose sum is σ = 1221023021514. Its totient is φ = 1221023021512.

The previous prime is 1221023021479. The next prime is 1221023021527. The reversal of 1221023021513 is 3151203201221.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 828842726464 + 392180295049 = 910408^2 + 626243^2 .

It is an emirp because it is prime and its reverse (3151203201221) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1221023021513 - 2²² = 1221018827209 is a prime.

It is not a weakly prime, because it can be changed into another prime (1221023021573) 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, 610511510756 + 610511510757.

It is an arithmetic number, because the mean of its divisors is an integer number (610511510757).

Almost surely, 2^{1221023021513} is an apocalyptic number.

It is an amenable number.

1221023021513 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221023021513 is an equidigital number, since it uses as much as digits as its factorization.

1221023021513 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 720, while the sum is 23.

Adding to 1221023021513 its reverse (3151203201221), we get a palindrome (4372226222734).

The spelling of 1221023021513 in words is "one trillion, two hundred twenty-one billion, twenty-three million, twenty-one thousand, five hundred thirteen".