138537610649 has 2 divisors, whose sum is σ = 138537610650. Its totient is φ = 138537610648.

The previous prime is 138537610643. The next prime is 138537610661. The reversal of 138537610649 is 946016735831.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 111062227600 + 27475383049 = 333260^2 + 165757^2 .

It is a cyclic number.

It is not a de Polignac number, because 138537610649 - 2²⁸ = 138269175193 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 138537610649.

It is not a weakly prime, because it can be changed into another prime (138537610643) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69268805324 + 69268805325.

It is an arithmetic number, because the mean of its divisors is an integer number (69268805325).

Almost surely, 2^138537610649 is an apocalyptic number.

It is an amenable number.

138537610649 is a deficient number, since it is larger than the sum of its proper divisors (1).

138537610649 is an equidigital number, since it uses as much as digits as its factorization.

138537610649 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3265920, while the sum is 53.

The spelling of 138537610649 in words is "one hundred thirty-eight billion, five hundred thirty-seven million, six hundred ten thousand, six hundred forty-nine".