138558320121 has 16 divisors (see below), whose sum is σ = 199997199360. Its totient is φ = 84820231680.

The previous prime is 138558320113. The next prime is 138558320129. The reversal of 138558320121 is 121023855831.

It is an interprime number because it is at equal distance from previous prime (138558320113) and next prime (138558320129).

It is not a de Polignac number, because 138558320121 - 2³ = 138558320113 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a self number, because there is not a number n which added to its sum of digits gives 138558320121.

It is not an unprimeable number, because it can be changed into a prime (138558320129) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9293016 + ... + 9307913.

It is an arithmetic number, because the mean of its divisors is an integer number (12499824960).

Almost surely, 2^138558320121 is an apocalyptic number.

It is an amenable number.

138558320121 is a deficient number, since it is larger than the sum of its proper divisors (61438879239).

138558320121 is a wasteful number, since it uses less digits than its factorization.

138558320121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18601136.

The product of its (nonzero) digits is 57600, while the sum is 39.

The spelling of 138558320121 in words is "one hundred thirty-eight billion, five hundred fifty-eight million, three hundred twenty thousand, one hundred twenty-one".