19664317 has 4 divisors (see below), whose sum is σ = 19689376. Its totient is φ = 19639260.

The previous prime is 19664273. The next prime is 19664341. The reversal of 19664317 is 71346691.

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.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-19664317 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19664357) 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 in 3 ways as a sum of consecutive naturals, for example, 11313 + ... + 12934.

It is an arithmetic number, because the mean of its divisors is an integer number (4922344).

Almost surely, 2^19664317 is an apocalyptic number.

It is an amenable number.

19664317 is a deficient number, since it is larger than the sum of its proper divisors (25059).

19664317 is an equidigital number, since it uses as much as digits as its factorization.

19664317 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25058.

The product of its digits is 27216, while the sum is 37.

The square root of 19664317 is about 4434.4466396609. The cubic root of 19664317 is about 269.9145454303.

The spelling of 19664317 in words is "nineteen million, six hundred sixty-four thousand, three hundred seventeen".