138428417 has 2 divisors, whose sum is σ = 138428418. Its totient is φ = 138428416.

The previous prime is 138428393. The next prime is 138428419. The reversal of 138428417 is 714824831.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 131997121 + 6431296 = 11489^2 + 2536^2 .

It is a cyclic number.

It is not a de Polignac number, because 138428417 - 2¹⁴ = 138412033 is a prime.

Together with 138428419, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (138428419) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69214208 + 69214209.

It is an arithmetic number, because the mean of its divisors is an integer number (69214209).

It is a Proth number, since it is equal to 8449 ⋅ 2¹⁴ + 1 and 8449 < 2¹⁴.

Almost surely, 2^138428417 is an apocalyptic number.

It is an amenable number.

138428417 is a deficient number, since it is larger than the sum of its proper divisors (1).

138428417 is an equidigital number, since it uses as much as digits as its factorization.

138428417 is an evil number, because the sum of its binary digits is even.

The product of its digits is 43008, while the sum is 38.

The square root of 138428417 is about 11765.5606326261. The cubic root of 138428417 is about 517.2991333831.

The spelling of 138428417 in words is "one hundred thirty-eight million, four hundred twenty-eight thousand, four hundred seventeen".