1323220991 has 2 divisors, whose sum is σ = 1323220992. Its totient is φ = 1323220990.

The previous prime is 1323220979. The next prime is 1323221017. The reversal of 1323220991 is 1990223231.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1323220991 - 2¹⁰ = 1323219967 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1323229991) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 661610495 + 661610496.

It is an arithmetic number, because the mean of its divisors is an integer number (661610496).

Almost surely, 2^1323220991 is an apocalyptic number.

1323220991 is a deficient number, since it is larger than the sum of its proper divisors (1).

1323220991 is an equidigital number, since it uses as much as digits as its factorization.

1323220991 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5832, while the sum is 32.

The square root of 1323220991 is about 36376.1046705114. The cubic root of 1323220991 is about 1097.8528338388.

The spelling of 1323220991 in words is "one billion, three hundred twenty-three million, two hundred twenty thousand, nine hundred ninety-one".