1919890309 has 2 divisors, whose sum is σ = 1919890310. Its totient is φ = 1919890308.

The previous prime is 1919890303. The next prime is 1919890327. The reversal of 1919890309 is 9030989191.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1301622084 + 618268225 = 36078^2 + 24865^2 .

It is a cyclic number.

It is not a de Polignac number, because 1919890309 - 2¹³ = 1919882117 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1919890303) 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, 959945154 + 959945155.

It is an arithmetic number, because the mean of its divisors is an integer number (959945155).

Almost surely, 2^1919890309 is an apocalyptic number.

It is an amenable number.

1919890309 is a deficient number, since it is larger than the sum of its proper divisors (1).

1919890309 is an equidigital number, since it uses as much as digits as its factorization.

1919890309 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 157464, while the sum is 49.

The square root of 1919890309 is about 43816.5529109719. The cubic root of 1919890309 is about 1242.8693328030.

The spelling of 1919890309 in words is "one billion, nine hundred nineteen million, eight hundred ninety thousand, three hundred nine".