19609649 has 2 divisors, whose sum is σ = 19609650. Its totient is φ = 19609648.

The previous prime is 19609643. The next prime is 19609651. The reversal of 19609649 is 94690691.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16120225 + 3489424 = 4015^2 + 1868^2 .

It is an emirp because it is prime and its reverse (94690691) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 19609649 - 2¹⁶ = 19544113 is a prime.

Together with 19609651, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (19609643) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9804824 + 9804825.

It is an arithmetic number, because the mean of its divisors is an integer number (9804825).

Almost surely, 2^19609649 is an apocalyptic number.

It is an amenable number.

19609649 is a deficient number, since it is larger than the sum of its proper divisors (1).

19609649 is an equidigital number, since it uses as much as digits as its factorization.

19609649 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 104976, while the sum is 44.

The square root of 19609649 is about 4428.2783336191. The cubic root of 19609649 is about 269.6641869861.

The spelling of 19609649 in words is "nineteen million, six hundred nine thousand, six hundred forty-nine".