13487521 has 2 divisors, whose sum is σ = 13487522. Its totient is φ = 13487520.

The previous prime is 13487519. The next prime is 13487531. The reversal of 13487521 is 12578431.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 7182400 + 6305121 = 2680^2 + 2511^2 .

It is a cyclic number.

It is not a de Polignac number, because 13487521 - 2¹ = 13487519 is a prime.

Together with 13487519, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (13487501) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6743760 + 6743761.

It is an arithmetic number, because the mean of its divisors is an integer number (6743761).

Almost surely, 2^13487521 is an apocalyptic number.

It is an amenable number.

13487521 is a deficient number, since it is larger than the sum of its proper divisors (1).

13487521 is an equidigital number, since it uses as much as digits as its factorization.

13487521 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 6720, while the sum is 31.

The square root of 13487521 is about 3672.5360447516. The cubic root of 13487521 is about 238.0367678525.

The spelling of 13487521 in words is "thirteen million, four hundred eighty-seven thousand, five hundred twenty-one".