13508821 has 2 divisors, whose sum is σ = 13508822. Its totient is φ = 13508820.

The previous prime is 13508819. The next prime is 13508849. The reversal of 13508821 is 12880531.

It is an a-pointer prime, because the next prime (13508849) can be obtained adding 13508821 to its sum of digits (28).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12680721 + 828100 = 3561^2 + 910^2 .

It is a cyclic number.

It is not a de Polignac number, because 13508821 - 2¹ = 13508819 is a prime.

Together with 13508819, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 13508821.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (13508801) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6754410 + 6754411.

It is an arithmetic number, because the mean of its divisors is an integer number (6754411).

Almost surely, 2^13508821 is an apocalyptic number.

It is an amenable number.

13508821 is a deficient number, since it is larger than the sum of its proper divisors (1).

13508821 is an equidigital number, since it uses as much as digits as its factorization.

13508821 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1920, while the sum is 28.

The square root of 13508821 is about 3675.4348042102. The cubic root of 13508821 is about 238.1620074842.

The spelling of 13508821 in words is "thirteen million, five hundred eight thousand, eight hundred twenty-one".