138209899 has 2 divisors, whose sum is σ = 138209900. Its totient is φ = 138209898.

The previous prime is 138209891. The next prime is 138209927. The reversal of 138209899 is 998902831.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 138209899 - 2³ = 138209891 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (138209891) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69104949 + 69104950.

It is an arithmetic number, because the mean of its divisors is an integer number (69104950).

Almost surely, 2^138209899 is an apocalyptic number.

138209899 is a deficient number, since it is larger than the sum of its proper divisors (1).

138209899 is an equidigital number, since it uses as much as digits as its factorization.

138209899 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 279936, while the sum is 49.

The square root of 138209899 is about 11756.2706246496. The cubic root of 138209899 is about 517.0267935786.

The spelling of 138209899 in words is "one hundred thirty-eight million, two hundred nine thousand, eight hundred ninety-nine".