138121427 has 2 divisors, whose sum is σ = 138121428. Its totient is φ = 138121426.

The previous prime is 138121411. The next prime is 138121429. The reversal of 138121427 is 724121831.

It is a strong prime.

It is an emirp because it is prime and its reverse (724121831) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 138121427 - 2⁴ = 138121411 is a prime.

Together with 138121429, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 138121427.

It is not a weakly prime, because it can be changed into another prime (138121429) 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, 69060713 + 69060714.

It is an arithmetic number, because the mean of its divisors is an integer number (69060714).

Almost surely, 2^138121427 is an apocalyptic number.

138121427 is a deficient number, since it is larger than the sum of its proper divisors (1).

138121427 is an equidigital number, since it uses as much as digits as its factorization.

138121427 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2688, while the sum is 29.

The square root of 138121427 is about 11752.5072644096. The cubic root of 138121427 is about 516.9164489540.

The spelling of 138121427 in words is "one hundred thirty-eight million, one hundred twenty-one thousand, four hundred twenty-seven".