1321303021 has 2 divisors, whose sum is σ = 1321303022. Its totient is φ = 1321303020.

The previous prime is 1321303013. The next prime is 1321303033. The reversal of 1321303021 is 1203031231.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 887205796 + 434097225 = 29786^2 + 20835^2 .

It is a cyclic number.

It is not a de Polignac number, because 1321303021 - 2³ = 1321303013 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1321302986 and 1321303004.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1321304021) 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, 660651510 + 660651511.

It is an arithmetic number, because the mean of its divisors is an integer number (660651511).

Almost surely, 2^1321303021 is an apocalyptic number.

It is an amenable number.

1321303021 is a deficient number, since it is larger than the sum of its proper divisors (1).

1321303021 is an equidigital number, since it uses as much as digits as its factorization.

1321303021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 108, while the sum is 16.

The square root of 1321303021 is about 36349.7320622862. The cubic root of 1321303021 is about 1097.3221421925.

Adding to 1321303021 its reverse (1203031231), we get a palindrome (2524334252).

The spelling of 1321303021 in words is "one billion, three hundred twenty-one million, three hundred three thousand, twenty-one".