138721099 has 8 divisors (see below), whose sum is σ = 151522560. Its totient is φ = 125951400.

The previous prime is 138721057. The next prime is 138721117. The reversal of 138721099 is 990127831.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 138721099 - 2¹⁵ = 138688331 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (138721019) 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 in 7 ways as a sum of consecutive naturals, for example, 1714 + ... + 16744.

It is an arithmetic number, because the mean of its divisors is an integer number (18940320).

Almost surely, 2^138721099 is an apocalyptic number.

138721099 is a deficient number, since it is larger than the sum of its proper divisors (12801461).

138721099 is a wasteful number, since it uses less digits than its factorization.

138721099 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15881.

The product of its (nonzero) digits is 27216, while the sum is 40.

The square root of 138721099 is about 11777.9921463720. The cubic root of 138721099 is about 517.6634554103.

The spelling of 138721099 in words is "one hundred thirty-eight million, seven hundred twenty-one thousand, ninety-nine".