138475121 has 2 divisors, whose sum is σ = 138475122. Its totient is φ = 138475120.

The previous prime is 138475091. The next prime is 138475123. The reversal of 138475121 is 121574831.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 119596096 + 18879025 = 10936^2 + 4345^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-138475121 is a prime.

It is a Sophie Germain prime.

Together with 138475123, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (138475123) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69237560 + 69237561.

It is an arithmetic number, because the mean of its divisors is an integer number (69237561).

Almost surely, 2^138475121 is an apocalyptic number.

It is an amenable number.

138475121 is a deficient number, since it is larger than the sum of its proper divisors (1).

138475121 is an equidigital number, since it uses as much as digits as its factorization.

138475121 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6720, while the sum is 32.

The square root of 138475121 is about 11767.5452410433. The cubic root of 138475121 is about 517.3573035736.

The spelling of 138475121 in words is "one hundred thirty-eight million, four hundred seventy-five thousand, one hundred twenty-one".