138428233 has 2 divisors, whose sum is σ = 138428234. Its totient is φ = 138428232.

The previous prime is 138428179. The next prime is 138428249. The reversal of 138428233 is 332824831.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 133818624 + 4609609 = 11568^2 + 2147^2 .

It is an emirp because it is prime and its reverse (332824831) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 138428233 - 2¹⁷ = 138297161 is a prime.

It is not a weakly prime, because it can be changed into another prime (138428333) 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, 69214116 + 69214117.

It is an arithmetic number, because the mean of its divisors is an integer number (69214117).

Almost surely, 2^138428233 is an apocalyptic number.

It is an amenable number.

138428233 is a deficient number, since it is larger than the sum of its proper divisors (1).

138428233 is an equidigital number, since it uses as much as digits as its factorization.

138428233 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 27648, while the sum is 34.

The square root of 138428233 is about 11765.5528131916. The cubic root of 138428233 is about 517.2989041839.

The spelling of 138428233 in words is "one hundred thirty-eight million, four hundred twenty-eight thousand, two hundred thirty-three".