1320405491 has 2 divisors, whose sum is σ = 1320405492. Its totient is φ = 1320405490.

The previous prime is 1320405481. The next prime is 1320405497. The reversal of 1320405491 is 1945040231.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1320405491 is a prime.

It is not a weakly prime, because it can be changed into another prime (1320405497) 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, 660202745 + 660202746.

It is an arithmetic number, because the mean of its divisors is an integer number (660202746).

Almost surely, 2^1320405491 is an apocalyptic number.

1320405491 is a deficient number, since it is larger than the sum of its proper divisors (1).

1320405491 is an equidigital number, since it uses as much as digits as its factorization.

1320405491 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4320, while the sum is 29.

The square root of 1320405491 is about 36337.3842069019. The cubic root of 1320405491 is about 1097.0736242238.

The spelling of 1320405491 in words is "one billion, three hundred twenty million, four hundred five thousand, four hundred ninety-one".