138681649979 has 2 divisors, whose sum is σ = 138681649980. Its totient is φ = 138681649978.

The previous prime is 138681649891. The next prime is 138681650039. The reversal of 138681649979 is 979946186831.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 138681649979 - 2²⁰ = 138680601403 is a prime.

It is not a weakly prime, because it can be changed into another prime (138681649079) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69340824989 + 69340824990.

It is an arithmetic number, because the mean of its divisors is an integer number (69340824990).

Almost surely, 2^138681649979 is an apocalyptic number.

138681649979 is a deficient number, since it is larger than the sum of its proper divisors (1).

138681649979 is an equidigital number, since it uses as much as digits as its factorization.

138681649979 is an evil number, because the sum of its binary digits is even.

The product of its digits is 141087744, while the sum is 71.

The spelling of 138681649979 in words is "one hundred thirty-eight billion, six hundred eighty-one million, six hundred forty-nine thousand, nine hundred seventy-nine".