19997317 has 2 divisors, whose sum is σ = 19997318. Its totient is φ = 19997316.

The previous prime is 19997297. The next prime is 19997333. The reversal of 19997317 is 71379991.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19838116 + 159201 = 4454^2 + 399^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-19997317 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (19997357) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 9998658 + 9998659.

It is an arithmetic number, because the mean of its divisors is an integer number (9998659).

Almost surely, 2^19997317 is an apocalyptic number.

It is an amenable number.

19997317 is a deficient number, since it is larger than the sum of its proper divisors (1).

19997317 is an equidigital number, since it uses as much as digits as its factorization.

19997317 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 107163, while the sum is 46.

The square root of 19997317 is about 4471.8359764195. The cubic root of 19997317 is about 271.4296231459.

It can be divided in two parts, 1999 and 7317, that added together give a triangular number (9316 = T₁₃₆).

The spelling of 19997317 in words is "nineteen million, nine hundred ninety-seven thousand, three hundred seventeen".