1321639019 has 2 divisors, whose sum is σ = 1321639020. Its totient is φ = 1321639018.

The previous prime is 1321639003. The next prime is 1321639021. The reversal of 1321639019 is 9109361231.

It is a strong prime.

It is an emirp because it is prime and its reverse (9109361231) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1321639019 - 2⁴ = 1321639003 is a prime.

It is a super-2 number, since 2×1321639019² = 3493459393086564722, which contains 22 as substring.

Together with 1321639021, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1321639019.

It is not a weakly prime, because it can be changed into another prime (1321639079) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 660819509 + 660819510.

It is an arithmetic number, because the mean of its divisors is an integer number (660819510).

Almost surely, 2^1321639019 is an apocalyptic number.

1321639019 is a deficient number, since it is larger than the sum of its proper divisors (1).

1321639019 is an equidigital number, since it uses as much as digits as its factorization.

1321639019 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8748, while the sum is 35.

The square root of 1321639019 is about 36354.3535082114. The cubic root of 1321639019 is about 1097.4151480590.

The spelling of 1321639019 in words is "one billion, three hundred twenty-one million, six hundred thirty-nine thousand, nineteen".