135811391 has 2 divisors, whose sum is σ = 135811392. Its totient is φ = 135811390.

The previous prime is 135811339. The next prime is 135811397. The reversal of 135811391 is 193118531.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-135811391 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (135811397) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 67905695 + 67905696.

It is an arithmetic number, because the mean of its divisors is an integer number (67905696).

Almost surely, 2^135811391 is an apocalyptic number.

135811391 is a deficient number, since it is larger than the sum of its proper divisors (1).

135811391 is an equidigital number, since it uses as much as digits as its factorization.

135811391 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3240, while the sum is 32.

The square root of 135811391 is about 11653.8144399162. The cubic root of 135811391 is about 514.0184793025.

The spelling of 135811391 in words is "one hundred thirty-five million, eight hundred eleven thousand, three hundred ninety-one".