1663323509 has 2 divisors, whose sum is σ = 1663323510. Its totient is φ = 1663323508.

The previous prime is 1663323491. The next prime is 1663323511. The reversal of 1663323509 is 9053233661.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1033815409 + 629508100 = 32153^2 + 25090^2 .

It is an emirp because it is prime and its reverse (9053233661) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1663323509 - 2⁸ = 1663323253 is a prime.

Together with 1663323511, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1663323209) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 831661754 + 831661755.

It is an arithmetic number, because the mean of its divisors is an integer number (831661755).

Almost surely, 2^1663323509 is an apocalyptic number.

It is an amenable number.

1663323509 is a deficient number, since it is larger than the sum of its proper divisors (1).

1663323509 is an equidigital number, since it uses as much as digits as its factorization.

1663323509 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 87480, while the sum is 38.

The square root of 1663323509 is about 40783.8633407871. The cubic root of 1663323509 is about 1184.8378205060.

The spelling of 1663323509 in words is "one billion, six hundred sixty-three million, three hundred twenty-three thousand, five hundred nine".