138599987 has 2 divisors, whose sum is σ = 138599988. Its totient is φ = 138599986.

The previous prime is 138599983. The next prime is 138600017. The reversal of 138599987 is 789995831.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 138599987 - 2² = 138599983 is a prime.

It is not a weakly prime, because it can be changed into another prime (138599983) 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, 69299993 + 69299994.

It is an arithmetic number, because the mean of its divisors is an integer number (69299994).

Almost surely, 2^138599987 is an apocalyptic number.

138599987 is a deficient number, since it is larger than the sum of its proper divisors (1).

138599987 is an equidigital number, since it uses as much as digits as its factorization.

138599987 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4898880, while the sum is 59.

The square root of 138599987 is about 11772.8495700913. The cubic root of 138599987 is about 517.5127609322.

The spelling of 138599987 in words is "one hundred thirty-eight million, five hundred ninety-nine thousand, nine hundred eighty-seven".