13659521 has 2 divisors, whose sum is σ = 13659522. Its totient is φ = 13659520.

The previous prime is 13659487. The next prime is 13659523. The reversal of 13659521 is 12595631.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 10491121 + 3168400 = 3239^2 + 1780^2 .

It is an emirp because it is prime and its reverse (12595631) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-13659521 is a prime.

It is a Sophie Germain prime.

Together with 13659523, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (13659523) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6829760 + 6829761.

It is an arithmetic number, because the mean of its divisors is an integer number (6829761).

Almost surely, 2^13659521 is an apocalyptic number.

It is an amenable number.

13659521 is a deficient number, since it is larger than the sum of its proper divisors (1).

13659521 is an equidigital number, since it uses as much as digits as its factorization.

13659521 is an evil number, because the sum of its binary digits is even.

The product of its digits is 8100, while the sum is 32.

The square root of 13659521 is about 3695.8789211769. The cubic root of 13659521 is about 239.0443537368.

The spelling of 13659521 in words is "thirteen million, six hundred fifty-nine thousand, five hundred twenty-one".