138989819 has 2 divisors, whose sum is σ = 138989820. Its totient is φ = 138989818.

The previous prime is 138989789. The next prime is 138989831. The reversal of 138989819 is 918989831.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 138989819 - 2⁸ = 138989563 is a prime.

It is a super-2 number, since 2×138989819² = 38636339571305522, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (138989849) 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, 69494909 + 69494910.

It is an arithmetic number, because the mean of its divisors is an integer number (69494910).

Almost surely, 2^138989819 is an apocalyptic number.

138989819 is a deficient number, since it is larger than the sum of its proper divisors (1).

138989819 is an equidigital number, since it uses as much as digits as its factorization.

138989819 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1119744, while the sum is 56.

The square root of 138989819 is about 11789.3943440704. The cubic root of 138989819 is about 517.9974992798.

The spelling of 138989819 in words is "one hundred thirty-eight million, nine hundred eighty-nine thousand, eight hundred nineteen".