19381009 has 2 divisors, whose sum is σ = 19381010. Its totient is φ = 19381008.

The previous prime is 19380971. The next prime is 19381027. The reversal of 19381009 is 90018391.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14745600 + 4635409 = 3840^2 + 2153^2 .

It is an emirp because it is prime and its reverse (90018391) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 19381009 - 2¹³ = 19372817 is a prime.

It is not a weakly prime, because it can be changed into another prime (19381039) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9690504 + 9690505.

It is an arithmetic number, because the mean of its divisors is an integer number (9690505).

Almost surely, 2^19381009 is an apocalyptic number.

It is an amenable number.

19381009 is a deficient number, since it is larger than the sum of its proper divisors (1).

19381009 is an equidigital number, since it uses as much as digits as its factorization.

19381009 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1944, while the sum is 31.

The square root of 19381009 is about 4402.3867390315. The cubic root of 19381009 is about 268.6120312921.

The spelling of 19381009 in words is "nineteen million, three hundred eighty-one thousand, nine".