138331181 has 2 divisors, whose sum is σ = 138331182. Its totient is φ = 138331180.

The previous prime is 138331139. The next prime is 138331183. The reversal of 138331181 is 181133831.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 131308681 + 7022500 = 11459^2 + 2650^2 .

It is a cyclic number.

It is not a de Polignac number, because 138331181 - 2⁶ = 138331117 is a prime.

It is a super-2 number, since 2×138331181² = 38271031273709522, which contains 22 as substring.

Together with 138331183, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (138331183) 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, 69165590 + 69165591.

It is an arithmetic number, because the mean of its divisors is an integer number (69165591).

Almost surely, 2^138331181 is an apocalyptic number.

It is an amenable number.

138331181 is a deficient number, since it is larger than the sum of its proper divisors (1).

138331181 is an equidigital number, since it uses as much as digits as its factorization.

138331181 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1728, while the sum is 29.

The square root of 138331181 is about 11761.4276769447. The cubic root of 138331181 is about 517.1779832089.

The spelling of 138331181 in words is "one hundred thirty-eight million, three hundred thirty-one thousand, one hundred eighty-one".