1321220513 has 2 divisors, whose sum is σ = 1321220514. Its totient is φ = 1321220512.

The previous prime is 1321220507. The next prime is 1321220519. The reversal of 1321220513 is 3150221231.

It is a balanced prime because it is at equal distance from previous prime (1321220507) and next prime (1321220519).

It can be written as a sum of positive squares in only one way, i.e., 676416064 + 644804449 = 26008^2 + 25393^2 .

It is a cyclic number.

It is not a de Polignac number, because 1321220513 - 2¹⁰ = 1321219489 is a prime.

It is not a weakly prime, because it can be changed into another prime (1321220519) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 660610256 + 660610257.

It is an arithmetic number, because the mean of its divisors is an integer number (660610257).

Almost surely, 2^1321220513 is an apocalyptic number.

It is an amenable number.

1321220513 is a deficient number, since it is larger than the sum of its proper divisors (1).

1321220513 is an equidigital number, since it uses as much as digits as its factorization.

1321220513 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 360, while the sum is 20.

The square root of 1321220513 is about 36348.5971256113. The cubic root of 1321220513 is about 1097.2993011690.

Adding to 1321220513 its reverse (3150221231), we get a palindrome (4471441744).

The spelling of 1321220513 in words is "one billion, three hundred twenty-one million, two hundred twenty thousand, five hundred thirteen".