135811261 has 2 divisors, whose sum is σ = 135811262. Its totient is φ = 135811260.

The previous prime is 135811253. The next prime is 135811267. The reversal of 135811261 is 162118531.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 126990361 + 8820900 = 11269^2 + 2970^2 .

It is a cyclic number.

It is not a de Polignac number, because 135811261 - 2³ = 135811253 is a prime.

It is a super-3 number, since 3×135811261³ (a number of 25 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (135811267) 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, 67905630 + 67905631.

It is an arithmetic number, because the mean of its divisors is an integer number (67905631).

Almost surely, 2^135811261 is an apocalyptic number.

It is an amenable number.

135811261 is a deficient number, since it is larger than the sum of its proper divisors (1).

135811261 is an equidigital number, since it uses as much as digits as its factorization.

135811261 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1440, while the sum is 28.

The square root of 135811261 is about 11653.8088623420. The cubic root of 135811261 is about 514.0183152946.

Adding to 135811261 its reverse (162118531), we get a palindrome (297929792).

The spelling of 135811261 in words is "one hundred thirty-five million, eight hundred eleven thousand, two hundred sixty-one".