1321438309 has 2 divisors, whose sum is σ = 1321438310. Its totient is φ = 1321438308.

The previous prime is 1321438301. The next prime is 1321438319. The reversal of 1321438309 is 9038341231.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 894189409 + 427248900 = 29903^2 + 20670^2 .

It is a cyclic number.

It is not a de Polignac number, because 1321438309 - 2³ = 1321438301 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1321438301) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 660719154 + 660719155.

It is an arithmetic number, because the mean of its divisors is an integer number (660719155).

Almost surely, 2^1321438309 is an apocalyptic number.

It is an amenable number.

1321438309 is a deficient number, since it is larger than the sum of its proper divisors (1).

1321438309 is an equidigital number, since it uses as much as digits as its factorization.

1321438309 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 15552, while the sum is 34.

The square root of 1321438309 is about 36351.5929362112. The cubic root of 1321438309 is about 1097.3595924592.

The spelling of 1321438309 in words is "one billion, three hundred twenty-one million, four hundred thirty-eight thousand, three hundred nine".