138245121517 has 2 divisors, whose sum is σ = 138245121518. Its totient is φ = 138245121516.

The previous prime is 138245121481. The next prime is 138245121563. The reversal of 138245121517 is 715121542831.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 125976014761 + 12269106756 = 354931^2 + 110766^2 .

It is a cyclic number.

It is not a de Polignac number, because 138245121517 - 2¹⁹ = 138244597229 is a prime.

It is a super-2 number, since 2×138245121517² (a number of 23 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 138245121517.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (138245121617) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69122560758 + 69122560759.

It is an arithmetic number, because the mean of its divisors is an integer number (69122560759).

Almost surely, 2^138245121517 is an apocalyptic number.

It is an amenable number.

138245121517 is a deficient number, since it is larger than the sum of its proper divisors (1).

138245121517 is an equidigital number, since it uses as much as digits as its factorization.

138245121517 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 67200, while the sum is 40.

The spelling of 138245121517 in words is "one hundred thirty-eight billion, two hundred forty-five million, one hundred twenty-one thousand, five hundred seventeen".