138686431097 has 2 divisors, whose sum is σ = 138686431098. Its totient is φ = 138686431096.

The previous prime is 138686431043. The next prime is 138686431139. The reversal of 138686431097 is 790134686831.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 116728822336 + 21957608761 = 341656^2 + 148181^2 .

It is a cyclic number.

It is not a de Polignac number, because 138686431097 - 2¹² = 138686427001 is a prime.

It is not a weakly prime, because it can be changed into another prime (138686431027) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69343215548 + 69343215549.

It is an arithmetic number, because the mean of its divisors is an integer number (69343215549).

Almost surely, 2^138686431097 is an apocalyptic number.

It is an amenable number.

138686431097 is a deficient number, since it is larger than the sum of its proper divisors (1).

138686431097 is an equidigital number, since it uses as much as digits as its factorization.

138686431097 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5225472, while the sum is 56.

The spelling of 138686431097 in words is "one hundred thirty-eight billion, six hundred eighty-six million, four hundred thirty-one thousand, ninety-seven".