8511521 has 2 divisors, whose sum is σ = 8511522. Its totient is φ = 8511520.

The previous prime is 8511511. The next prime is 8511523. The reversal of 8511521 is 1251158.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 4669921 + 3841600 = 2161^2 + 1960^2 .

It is a cyclic number.

It is not a de Polignac number, because 8511521 - 2⁶ = 8511457 is a prime.

Together with 8511523, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (8511523) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4255760 + 4255761.

It is an arithmetic number, because the mean of its divisors is an integer number (4255761).

Almost surely, 2^8511521 is an apocalyptic number.

It is an amenable number.

8511521 is a deficient number, since it is larger than the sum of its proper divisors (1).

8511521 is an equidigital number, since it uses as much as digits as its factorization.

8511521 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 400, while the sum is 23.

The square root of 8511521 is about 2917.4511135579. The cubic root of 8511521 is about 204.1749188575.

Adding to 8511521 its reverse (1251158), we get a palindrome (9762679).

The spelling of 8511521 in words is "eight million, five hundred eleven thousand, five hundred twenty-one".