138487989320491 has 2 divisors, whose sum is σ = 138487989320492. Its totient is φ = 138487989320490.

The previous prime is 138487989320459. The next prime is 138487989320509. The reversal of 138487989320491 is 194023989784831.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 138487989320491 - 2⁵ = 138487989320459 is a prime.

It is not a weakly prime, because it can be changed into another prime (138487989320411) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69243994660245 + 69243994660246.

It is an arithmetic number, because the mean of its divisors is an integer number (69243994660246).

Almost surely, 2^{138487989320491} is an apocalyptic number.

138487989320491 is a deficient number, since it is larger than the sum of its proper divisors (1).

138487989320491 is an equidigital number, since it uses as much as digits as its factorization.

138487989320491 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 752467968, while the sum is 76.

The spelling of 138487989320491 in words is "one hundred thirty-eight trillion, four hundred eighty-seven billion, nine hundred eighty-nine million, three hundred twenty thousand, four hundred ninety-one".