138535817617 has 2 divisors, whose sum is σ = 138535817618. Its totient is φ = 138535817616.

The previous prime is 138535817593. The next prime is 138535817663. The reversal of 138535817617 is 716718535831.

It is a Cunningham number, because it is equal to 372204²+1.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 138535817616 + 1 = 372204^2 + 1^2 .

It is a cyclic number.

It is not a de Polignac number, because 138535817617 - 2⁷ = 138535817489 is a prime.

It is not a weakly prime, because it can be changed into another prime (138535817117) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69267908808 + 69267908809.

It is an arithmetic number, because the mean of its divisors is an integer number (69267908809).

Almost surely, 2^138535817617 is an apocalyptic number.

It is an amenable number.

138535817617 is a deficient number, since it is larger than the sum of its proper divisors (1).

138535817617 is an equidigital number, since it uses as much as digits as its factorization.

138535817617 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4233600, while the sum is 55.

The spelling of 138535817617 in words is "one hundred thirty-eight billion, five hundred thirty-five million, eight hundred seventeen thousand, six hundred seventeen".