138815899 has 2 divisors, whose sum is σ = 138815900. Its totient is φ = 138815898.

The previous prime is 138815891. The next prime is 138815933. The reversal of 138815899 is 998518831.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 138815899 - 2³ = 138815891 is a prime.

It is not a weakly prime, because it can be changed into another prime (138815891) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69407949 + 69407950.

It is an arithmetic number, because the mean of its divisors is an integer number (69407950).

Almost surely, 2^138815899 is an apocalyptic number.

138815899 is a deficient number, since it is larger than the sum of its proper divisors (1).

138815899 is an equidigital number, since it uses as much as digits as its factorization.

138815899 is an evil number, because the sum of its binary digits is even.

The product of its digits is 622080, while the sum is 52.

The square root of 138815899 is about 11782.0159140955. The cubic root of 138815899 is about 517.7813498072.

The spelling of 138815899 in words is "one hundred thirty-eight million, eight hundred fifteen thousand, eight hundred ninety-nine".