138579478517 has 2 divisors, whose sum is σ = 138579478518. Its totient is φ = 138579478516.

The previous prime is 138579478489. The next prime is 138579478673. The reversal of 138579478517 is 715874975831.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 90737103076 + 47842375441 = 301226^2 + 218729^2 .

It is a cyclic number.

It is not a de Polignac number, because 138579478517 - 2¹⁶ = 138579412981 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (138579478217) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69289739258 + 69289739259.

It is an arithmetic number, because the mean of its divisors is an integer number (69289739259).

Almost surely, 2^138579478517 is an apocalyptic number.

It is an amenable number.

138579478517 is a deficient number, since it is larger than the sum of its proper divisors (1).

138579478517 is an equidigital number, since it uses as much as digits as its factorization.

138579478517 is an evil number, because the sum of its binary digits is even.

The product of its digits is 59270400, while the sum is 65.

The spelling of 138579478517 in words is "one hundred thirty-eight billion, five hundred seventy-nine million, four hundred seventy-eight thousand, five hundred seventeen".