135842521 has 2 divisors, whose sum is σ = 135842522. Its totient is φ = 135842520.

The previous prime is 135842513. The next prime is 135842557. The reversal of 135842521 is 125248531.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 134304921 + 1537600 = 11589^2 + 1240^2 .

It is an emirp because it is prime and its reverse (125248531) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 135842521 - 2³ = 135842513 is a prime.

It is not a weakly prime, because it can be changed into another prime (135842501) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 67921260 + 67921261.

It is an arithmetic number, because the mean of its divisors is an integer number (67921261).

Almost surely, 2^135842521 is an apocalyptic number.

It is an amenable number.

135842521 is a deficient number, since it is larger than the sum of its proper divisors (1).

135842521 is an equidigital number, since it uses as much as digits as its factorization.

135842521 is an evil number, because the sum of its binary digits is even.

The product of its digits is 9600, while the sum is 31.

The square root of 135842521 is about 11655.1499775850. The cubic root of 135842521 is about 514.0577498740.

The spelling of 135842521 in words is "one hundred thirty-five million, eight hundred forty-two thousand, five hundred twenty-one".