138904736857 has 2 divisors, whose sum is σ = 138904736858. Its totient is φ = 138904736856.

The previous prime is 138904736833. The next prime is 138904736891. The reversal of 138904736857 is 758637409831.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 94432675401 + 44472061456 = 307299^2 + 210884^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-138904736857 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 138904736795 and 138904736804.

It is not a weakly prime, because it can be changed into another prime (138904736827) 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 as a sum of consecutive naturals, namely, 69452368428 + 69452368429.

It is an arithmetic number, because the mean of its divisors is an integer number (69452368429).

Almost surely, 2^138904736857 is an apocalyptic number.

It is an amenable number.

138904736857 is a deficient number, since it is larger than the sum of its proper divisors (1).

138904736857 is an equidigital number, since it uses as much as digits as its factorization.

138904736857 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 30481920, while the sum is 61.

The spelling of 138904736857 in words is "one hundred thirty-eight billion, nine hundred four million, seven hundred thirty-six thousand, eight hundred fifty-seven".