138547949 has 2 divisors, whose sum is σ = 138547950. Its totient is φ = 138547948.

The previous prime is 138547889. The next prime is 138547951. The reversal of 138547949 is 949745831.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 90592324 + 47955625 = 9518^2 + 6925^2 .

It is a cyclic number.

It is not a de Polignac number, because 138547949 - 2⁸ = 138547693 is a prime.

Together with 138547951, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 138547897 and 138547906.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (138547049) 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, 69273974 + 69273975.

It is an arithmetic number, because the mean of its divisors is an integer number (69273975).

Almost surely, 2^138547949 is an apocalyptic number.

It is an amenable number.

138547949 is a deficient number, since it is larger than the sum of its proper divisors (1).

138547949 is an equidigital number, since it uses as much as digits as its factorization.

138547949 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1088640, while the sum is 50.

The square root of 138547949 is about 11770.6392774564. The cubic root of 138547949 is about 517.4479853125.

The spelling of 138547949 in words is "one hundred thirty-eight million, five hundred forty-seven thousand, nine hundred forty-nine".