19808449 has 2 divisors, whose sum is σ = 19808450. Its totient is φ = 19808448.

The previous prime is 19808443. The next prime is 19808491. The reversal of 19808449 is 94480891.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13927824 + 5880625 = 3732^2 + 2425^2 .

It is an emirp because it is prime and its reverse (94480891) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 19808449 - 2¹¹ = 19806401 is a prime.

It is not a weakly prime, because it can be changed into another prime (19808443) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9904224 + 9904225.

It is an arithmetic number, because the mean of its divisors is an integer number (9904225).

Almost surely, 2^19808449 is an apocalyptic number.

It is an amenable number.

19808449 is a deficient number, since it is larger than the sum of its proper divisors (1).

19808449 is an equidigital number, since it uses as much as digits as its factorization.

19808449 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 82944, while the sum is 43.

The square root of 19808449 is about 4450.6683767722. The cubic root of 19808449 is about 270.5723979175.

The spelling of 19808449 in words is "nineteen million, eight hundred eight thousand, four hundred forty-nine".