138531108761 has 2 divisors, whose sum is σ = 138531108762. Its totient is φ = 138531108760.

The previous prime is 138531108743. The next prime is 138531108827. The reversal of 138531108761 is 167801135831.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 128164000000 + 10367108761 = 358000^2 + 101819^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-138531108761 is a prime.

It is not a weakly prime, because it can be changed into another prime (138531108721) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69265554380 + 69265554381.

It is an arithmetic number, because the mean of its divisors is an integer number (69265554381).

Almost surely, 2^138531108761 is an apocalyptic number.

It is an amenable number.

138531108761 is a deficient number, since it is larger than the sum of its proper divisors (1).

138531108761 is an equidigital number, since it uses as much as digits as its factorization.

138531108761 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 120960, while the sum is 44.

The spelling of 138531108761 in words is "one hundred thirty-eight billion, five hundred thirty-one million, one hundred eight thousand, seven hundred sixty-one".