138555449 has 2 divisors, whose sum is σ = 138555450. Its totient is φ = 138555448.

The previous prime is 138555437. The next prime is 138555451. The reversal of 138555449 is 944555831.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 76650025 + 61905424 = 8755^2 + 7868^2 .

It is an emirp because it is prime and its reverse (944555831) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 138555449 - 2⁴ = 138555433 is a prime.

It is a super-2 number, since 2×138555449² = 38395224895183202, which contains 22 as substring.

Together with 138555451, 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 (138551449) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69277724 + 69277725.

It is an arithmetic number, because the mean of its divisors is an integer number (69277725).

Almost surely, 2^138555449 is an apocalyptic number.

It is an amenable number.

138555449 is a deficient number, since it is larger than the sum of its proper divisors (1).

138555449 is an equidigital number, since it uses as much as digits as its factorization.

138555449 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 432000, while the sum is 44.

The square root of 138555449 is about 11770.9578624681. The cubic root of 138555449 is about 517.4573221279.

The spelling of 138555449 in words is "one hundred thirty-eight million, five hundred fifty-five thousand, four hundred forty-nine".