8915521 has 2 divisors, whose sum is σ = 8915522. Its totient is φ = 8915520.

The previous prime is 8915519. The next prime is 8915537. The reversal of 8915521 is 1255198.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 8410000 + 505521 = 2900^2 + 711^2 .

It is a cyclic number.

It is not a de Polignac number, because 8915521 - 2¹ = 8915519 is a prime.

Together with 8915519, it forms a pair of twin primes.

It is a Chen prime.

8915521 is a lucky number.

It is not a weakly prime, because it can be changed into another prime (8915551) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4457760 + 4457761.

It is an arithmetic number, because the mean of its divisors is an integer number (4457761).

Almost surely, 2^8915521 is an apocalyptic number.

It is an amenable number.

8915521 is a deficient number, since it is larger than the sum of its proper divisors (1).

8915521 is an equidigital number, since it uses as much as digits as its factorization.

8915521 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3600, while the sum is 31.

The square root of 8915521 is about 2985.8869703992. The cubic root of 8915521 is about 207.3555078645.

The spelling of 8915521 in words is "eight million, nine hundred fifteen thousand, five hundred twenty-one".