135438181 has 2 divisors, whose sum is σ = 135438182. Its totient is φ = 135438180.

The previous prime is 135438179. The next prime is 135438187. The reversal of 135438181 is 181834531.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 117722500 + 17715681 = 10850^2 + 4209^2 .

It is a cyclic number.

It is not a de Polignac number, because 135438181 - 2¹ = 135438179 is a prime.

It is a super-2 number, since 2×135438181² = 36687001745177522, which contains 22 as substring.

Together with 135438179, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (135438187) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 67719090 + 67719091.

It is an arithmetic number, because the mean of its divisors is an integer number (67719091).

Almost surely, 2^135438181 is an apocalyptic number.

It is an amenable number.

135438181 is a deficient number, since it is larger than the sum of its proper divisors (1).

135438181 is an equidigital number, since it uses as much as digits as its factorization.

135438181 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 11520, while the sum is 34.

The square root of 135438181 is about 11637.7910704738. The cubic root of 135438181 is about 513.5472060495.

The spelling of 135438181 in words is "one hundred thirty-five million, four hundred thirty-eight thousand, one hundred eighty-one".