138122111022121 has 4 divisors (see below), whose sum is σ = 138163601596500. Its totient is φ = 138080620447744.

The previous prime is 138122111022031. The next prime is 138122111022149. The reversal of 138122111022121 is 121220111221831.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 43414393881600 + 94707717140521 = 6588960^2 + 9731789^2 .

It is a cyclic number.

It is not a de Polignac number, because 138122111022121 - 2¹¹ = 138122111020073 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 138122111022121.

It is not an unprimeable number, because it can be changed into a prime (138122111022821) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 20745282196 + ... + 20745288853.

It is an arithmetic number, because the mean of its divisors is an integer number (34540900399125).

Almost surely, 2^{138122111022121} is an apocalyptic number.

It is an amenable number.

138122111022121 is a deficient number, since it is larger than the sum of its proper divisors (41490574379).

138122111022121 is an equidigital number, since it uses as much as digits as its factorization.

138122111022121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41490574378.

The product of its (nonzero) digits is 768, while the sum is 28.

Adding to 138122111022121 its reverse (121220111221831), we get a palindrome (259342222243952).

The spelling of 138122111022121 in words is "one hundred thirty-eight trillion, one hundred twenty-two billion, one hundred eleven million, twenty-two thousand, one hundred twenty-one".