138264391 has 2 divisors, whose sum is σ = 138264392. Its totient is φ = 138264390.

The previous prime is 138264337. The next prime is 138264397. The reversal of 138264391 is 193462831.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 138264391 - 2¹⁷ = 138133319 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 138264391.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (138264397) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69132195 + 69132196.

It is an arithmetic number, because the mean of its divisors is an integer number (69132196).

Almost surely, 2^138264391 is an apocalyptic number.

138264391 is a deficient number, since it is larger than the sum of its proper divisors (1).

138264391 is an equidigital number, since it uses as much as digits as its factorization.

138264391 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 31104, while the sum is 37.

The square root of 138264391 is about 11758.5879679492. The cubic root of 138264391 is about 517.0947340141.

The spelling of 138264391 in words is "one hundred thirty-eight million, two hundred sixty-four thousand, three hundred ninety-one".