138029809 has 2 divisors, whose sum is σ = 138029810. Its totient is φ = 138029808.

The previous prime is 138029807. The next prime is 138029873. The reversal of 138029809 is 908920831.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 136819809 + 1210000 = 11697^2 + 1100^2 .

It is a cyclic number.

It is not a de Polignac number, because 138029809 - 2¹ = 138029807 is a prime.

Together with 138029807, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (138029807) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69014904 + 69014905.

It is an arithmetic number, because the mean of its divisors is an integer number (69014905).

Almost surely, 2^138029809 is an apocalyptic number.

It is an amenable number.

138029809 is a deficient number, since it is larger than the sum of its proper divisors (1).

138029809 is an equidigital number, since it uses as much as digits as its factorization.

138029809 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 31104, while the sum is 40.

The square root of 138029809 is about 11748.6088112593. The cubic root of 138029809 is about 516.8021308804.

The spelling of 138029809 in words is "one hundred thirty-eight million, twenty-nine thousand, eight hundred nine".