135683521 has 2 divisors, whose sum is σ = 135683522. Its totient is φ = 135683520.

The previous prime is 135683519. The next prime is 135683531. The reversal of 135683521 is 125386531.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 131997121 + 3686400 = 11489^2 + 1920^2 .

It is an emirp because it is prime and its reverse (125386531) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 135683521 - 2¹ = 135683519 is a prime.

Together with 135683519, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (135683531) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 67841760 + 67841761.

It is an arithmetic number, because the mean of its divisors is an integer number (67841761).

Almost surely, 2^135683521 is an apocalyptic number.

It is an amenable number.

135683521 is a deficient number, since it is larger than the sum of its proper divisors (1).

135683521 is an equidigital number, since it uses as much as digits as its factorization.

135683521 is an evil number, because the sum of its binary digits is even.

The product of its digits is 21600, while the sum is 34.

The square root of 135683521 is about 11648.3269614138. The cubic root of 135683521 is about 513.8571080034.

The spelling of 135683521 in words is "one hundred thirty-five million, six hundred eighty-three thousand, five hundred twenty-one".