19987317 has 20 divisors (see below), whose sum is σ = 34123936. Its totient is φ = 11421000.

The previous prime is 19987309. The next prime is 19987333. The reversal of 19987317 is 71378991.

It is not a de Polignac number, because 19987317 - 2³ = 19987309 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19987367) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 17059 + ... + 18192.

Almost surely, 2^19987317 is an apocalyptic number.

It is an amenable number.

19987317 is a deficient number, since it is larger than the sum of its proper divisors (14136619).

19987317 is an equidigital number, since it uses as much as digits as its factorization.

19987317 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 35270 (or 35261 counting only the distinct ones).

The product of its digits is 95256, while the sum is 45.

The square root of 19987317 is about 4470.7177276138. The cubic root of 19987317 is about 271.3843712620.

The spelling of 19987317 in words is "nineteen million, nine hundred eighty-seven thousand, three hundred seventeen".