19688609 has 4 divisors (see below), whose sum is σ = 19729200. Its totient is φ = 19648020.

The previous prime is 19688597. The next prime is 19688623. The reversal of 19688609 is 90688691.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 90688691 = 19 ⋅4773089.

It is a cyclic number.

It is not a de Polignac number, because 19688609 - 2⁸ = 19688353 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (19681609) 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 in 3 ways as a sum of consecutive naturals, for example, 19559 + ... + 20540.

It is an arithmetic number, because the mean of its divisors is an integer number (4932300).

Almost surely, 2^19688609 is an apocalyptic number.

It is an amenable number.

19688609 is a deficient number, since it is larger than the sum of its proper divisors (40591).

19688609 is an equidigital number, since it uses as much as digits as its factorization.

19688609 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40590.

The product of its (nonzero) digits is 186624, while the sum is 47.

The square root of 19688609 is about 4437.1848057073. The cubic root of 19688609 is about 270.0256445692.

The spelling of 19688609 in words is "nineteen million, six hundred eighty-eight thousand, six hundred nine".