8717499221 has 2 divisors, whose sum is σ = 8717499222. Its totient is φ = 8717499220.

The previous prime is 8717499191. The next prime is 8717499239. The reversal of 8717499221 is 1229947178.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 7901254321 + 816244900 = 88889^2 + 28570^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-8717499221 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 8717499221.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (8717499121) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4358749610 + 4358749611.

It is an arithmetic number, because the mean of its divisors is an integer number (4358749611).

Almost surely, 2^8717499221 is an apocalyptic number.

It is an amenable number.

8717499221 is a deficient number, since it is larger than the sum of its proper divisors (1).

8717499221 is an equidigital number, since it uses as much as digits as its factorization.

8717499221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 508032, while the sum is 50.

The square root of 8717499221 is about 93367.5490788957. The cubic root of 8717499221 is about 2058.0881514964.

The spelling of 8717499221 in words is "eight billion, seven hundred seventeen million, four hundred ninety-nine thousand, two hundred twenty-one".