138888331 has 2 divisors, whose sum is σ = 138888332. Its totient is φ = 138888330.

The previous prime is 138888319. The next prime is 138888341. The reversal of 138888331 is 133888831.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 138888331 - 2¹¹ = 138886283 is a prime.

It is a super-2 number, since 2×138888331² = 38579936975931122, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (138888341) 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, 69444165 + 69444166.

It is an arithmetic number, because the mean of its divisors is an integer number (69444166).

Almost surely, 2^138888331 is an apocalyptic number.

138888331 is a deficient number, since it is larger than the sum of its proper divisors (1).

138888331 is an equidigital number, since it uses as much as digits as its factorization.

138888331 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 110592, while the sum is 43.

The square root of 138888331 is about 11785.0893505310. The cubic root of 138888331 is about 517.8713909285.

The spelling of 138888331 in words is "one hundred thirty-eight million, eight hundred eighty-eight thousand, three hundred thirty-one".