135544781 has 2 divisors, whose sum is σ = 135544782. Its totient is φ = 135544780.

The previous prime is 135544763. The next prime is 135544813. The reversal of 135544781 is 187445531.

135544781 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 91202500 + 44342281 = 9550^2 + 6659^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-135544781 is a prime.

It is a super-2 number, since 2×135544781² = 36744775312675922, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (135541781) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 67772390 + 67772391.

It is an arithmetic number, because the mean of its divisors is an integer number (67772391).

Almost surely, 2^135544781 is an apocalyptic number.

It is an amenable number.

135544781 is a deficient number, since it is larger than the sum of its proper divisors (1).

135544781 is an equidigital number, since it uses as much as digits as its factorization.

135544781 is an evil number, because the sum of its binary digits is even.

The product of its digits is 67200, while the sum is 38.

The square root of 135544781 is about 11642.3700765781. The cubic root of 135544781 is about 513.6819040976.

The spelling of 135544781 in words is "one hundred thirty-five million, five hundred forty-four thousand, seven hundred eighty-one".