8991517 has 2 divisors, whose sum is σ = 8991518. Its totient is φ = 8991516.

The previous prime is 8991449. The next prime is 8991529. The reversal of 8991517 is 7151998.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 8608356 + 383161 = 2934^2 + 619^2 .

It is a cyclic number.

It is not a de Polignac number, because 8991517 - 2¹¹ = 8989469 is a prime.

It is a super-2 number, since 2×8991517² = 161694755922578, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 8991517.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (8997517) 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 as a sum of consecutive naturals, namely, 4495758 + 4495759.

It is an arithmetic number, because the mean of its divisors is an integer number (4495759).

Almost surely, 2^8991517 is an apocalyptic number.

It is an amenable number.

8991517 is a deficient number, since it is larger than the sum of its proper divisors (1).

8991517 is an equidigital number, since it uses as much as digits as its factorization.

8991517 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 22680, while the sum is 40.

The square root of 8991517 is about 2998.5858333555. The cubic root of 8991517 is about 207.9430086093.

The spelling of 8991517 in words is "eight million, nine hundred ninety-one thousand, five hundred seventeen".