138658469 has 2 divisors, whose sum is σ = 138658470. Its totient is φ = 138658468.

The previous prime is 138658459. The next prime is 138658519. The reversal of 138658469 is 964856831.

It is an a-pointer prime, because the next prime (138658519) can be obtained adding 138658469 to its sum of digits (50).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 137194369 + 1464100 = 11713^2 + 1210^2 .

It is a cyclic number.

It is not a de Polignac number, because 138658469 - 2⁴ = 138658453 is a prime.

It is a super-2 number, since 2×138658469² = 38452342050847922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (138658459) 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, 69329234 + 69329235.

It is an arithmetic number, because the mean of its divisors is an integer number (69329235).

Almost surely, 2^138658469 is an apocalyptic number.

It is an amenable number.

138658469 is a deficient number, since it is larger than the sum of its proper divisors (1).

138658469 is an equidigital number, since it uses as much as digits as its factorization.

138658469 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1244160, while the sum is 50.

The square root of 138658469 is about 11775.3330738455. Note that the first 3 decimals coincide. The cubic root of 138658469 is about 517.5855385376.

The spelling of 138658469 in words is "one hundred thirty-eight million, six hundred fifty-eight thousand, four hundred sixty-nine".