138985991873 has 2 divisors, whose sum is σ = 138985991874. Its totient is φ = 138985991872.

The previous prime is 138985991849. The next prime is 138985991891. The reversal of 138985991873 is 378199589831.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 84072162304 + 54913829569 = 289952^2 + 234337^2 .

It is a cyclic number.

It is not a de Polignac number, because 138985991873 - 2³⁴ = 121806122689 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 138985991797 and 138985991806.

It is not a weakly prime, because it can be changed into another prime (138985997873) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69492995936 + 69492995937.

It is an arithmetic number, because the mean of its divisors is an integer number (69492995937).

Almost surely, 2^138985991873 is an apocalyptic number.

It is an amenable number.

138985991873 is a deficient number, since it is larger than the sum of its proper divisors (1).

138985991873 is an equidigital number, since it uses as much as digits as its factorization.

138985991873 is an evil number, because the sum of its binary digits is even.

The product of its digits is 117573120, while the sum is 71.

The spelling of 138985991873 in words is "one hundred thirty-eight billion, nine hundred eighty-five million, nine hundred ninety-one thousand, eight hundred seventy-three".