138412908521 has 2 divisors, whose sum is σ = 138412908522. Its totient is φ = 138412908520.

The previous prime is 138412908451. The next prime is 138412908533. The reversal of 138412908521 is 125809214831.

138412908521 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 138282834496 + 130074025 = 371864^2 + 11405^2 .

It is a cyclic number.

It is not a de Polignac number, because 138412908521 - 2³⁰ = 137339166697 is a prime.

It is not a weakly prime, because it can be changed into another prime (138412908551) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69206454260 + 69206454261.

It is an arithmetic number, because the mean of its divisors is an integer number (69206454261).

Almost surely, 2^138412908521 is an apocalyptic number.

It is an amenable number.

138412908521 is a deficient number, since it is larger than the sum of its proper divisors (1).

138412908521 is an equidigital number, since it uses as much as digits as its factorization.

138412908521 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 138240, while the sum is 44.

The spelling of 138412908521 in words is "one hundred thirty-eight billion, four hundred twelve million, nine hundred eight thousand, five hundred twenty-one".