13506509 has 2 divisors, whose sum is σ = 13506510. Its totient is φ = 13506508.

The previous prime is 13506481. The next prime is 13506523. The reversal of 13506509 is 90560531.

13506509 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 10956100 + 2550409 = 3310^2 + 1597^2 .

It is a cyclic number.

It is not a de Polignac number, because 13506509 - 2¹² = 13502413 is a prime.

It is a plaindrome in base 15.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (13506529) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6753254 + 6753255.

It is an arithmetic number, because the mean of its divisors is an integer number (6753255).

Almost surely, 2^13506509 is an apocalyptic number.

It is an amenable number.

13506509 is a deficient number, since it is larger than the sum of its proper divisors (1).

13506509 is an equidigital number, since it uses as much as digits as its factorization.

13506509 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4050, while the sum is 29.

The square root of 13506509 is about 3675.1202701408. The cubic root of 13506509 is about 238.1484197705.

The spelling of 13506509 in words is "thirteen million, five hundred six thousand, five hundred nine".