8971499521 has 2 divisors, whose sum is σ = 8971499522. Its totient is φ = 8971499520.

The previous prime is 8971499519. The next prime is 8971499561. The reversal of 8971499521 is 1259941798.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 5545036225 + 3426463296 = 74465^2 + 58536^2 .

It is a cyclic number.

It is not a de Polignac number, because 8971499521 - 2¹ = 8971499519 is a prime.

Together with 8971499519, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (8971499561) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4485749760 + 4485749761.

It is an arithmetic number, because the mean of its divisors is an integer number (4485749761).

Almost surely, 2^8971499521 is an apocalyptic number.

It is an amenable number.

8971499521 is a deficient number, since it is larger than the sum of its proper divisors (1).

8971499521 is an equidigital number, since it uses as much as digits as its factorization.

8971499521 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1632960, while the sum is 55.

The square root of 8971499521 is about 94717.9999841635. Note that the first 4 decimals coincide. The cubic root of 8971499521 is about 2077.8858203259.

The spelling of 8971499521 in words is "eight billion, nine hundred seventy-one million, four hundred ninety-nine thousand, five hundred twenty-one".