138985999979 has 4 divisors (see below), whose sum is σ = 139047310584. Its totient is φ = 138924689376.

The previous prime is 138985999973. The next prime is 138985999991. The reversal of 138985999979 is 979999589831.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 979999589831 = 77137 ⋅12704663.

It is a cyclic number.

It is not a de Polignac number, because 138985999979 - 2⁴ = 138985999963 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 138985999979.

It is not an unprimeable number, because it can be changed into a prime (138985999973) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 30651902 + ... + 30656435.

It is an arithmetic number, because the mean of its divisors is an integer number (34761827646).

Almost surely, 2^138985999979 is an apocalyptic number.

138985999979 is a deficient number, since it is larger than the sum of its proper divisors (61310605).

138985999979 is an equidigital number, since it uses as much as digits as its factorization.

138985999979 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 61310604.

The product of its digits is 3571283520, while the sum is 86.

The spelling of 138985999979 in words is "one hundred thirty-eight billion, nine hundred eighty-five million, nine hundred ninety-nine thousand, nine hundred seventy-nine".