13431521 has 2 divisors, whose sum is σ = 13431522. Its totient is φ = 13431520.

The previous prime is 13431503. The next prime is 13431533. The reversal of 13431521 is 12513431.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 8761600 + 4669921 = 2960^2 + 2161^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-13431521 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 13431493 and 13431502.

It is not a weakly prime, because it can be changed into another prime (13431541) 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, 6715760 + 6715761.

It is an arithmetic number, because the mean of its divisors is an integer number (6715761).

Almost surely, 2^13431521 is an apocalyptic number.

It is an amenable number.

13431521 is a deficient number, since it is larger than the sum of its proper divisors (1).

13431521 is an equidigital number, since it uses as much as digits as its factorization.

13431521 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 360, while the sum is 20.

The square root of 13431521 is about 3664.9039550853. The cubic root of 13431521 is about 237.7068690665.

Adding to 13431521 its reverse (12513431), we get a palindrome (25944952).

The spelling of 13431521 in words is "thirteen million, four hundred thirty-one thousand, five hundred twenty-one".