998172517 has 2 divisors, whose sum is σ = 998172518. Its totient is φ = 998172516.

The previous prime is 998172509. The next prime is 998172521. The reversal of 998172517 is 715271899.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 589081441 + 409091076 = 24271^2 + 20226^2 .

It is a cyclic number.

It is not a de Polignac number, because 998172517 - 2³ = 998172509 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (998172577) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 499086258 + 499086259.

It is an arithmetic number, because the mean of its divisors is an integer number (499086259).

Almost surely, 2^998172517 is an apocalyptic number.

It is an amenable number.

998172517 is a deficient number, since it is larger than the sum of its proper divisors (1).

998172517 is an equidigital number, since it uses as much as digits as its factorization.

998172517 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 317520, while the sum is 49.

The square root of 998172517 is about 31593.8683449811. The cubic root of 998172517 is about 999.3904675457.

The spelling of 998172517 in words is "nine hundred ninety-eight million, one hundred seventy-two thousand, five hundred seventeen".