139781239817 has 2 divisors, whose sum is σ = 139781239818. Its totient is φ = 139781239816.

The previous prime is 139781239813. The next prime is 139781239861. The reversal of 139781239817 is 718932187931.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 133333792201 + 6447447616 = 365149^2 + 80296^2 .

It is a cyclic number.

It is not a de Polignac number, because 139781239817 - 2² = 139781239813 is a prime.

It is not a weakly prime, because it can be changed into another prime (139781239811) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69890619908 + 69890619909.

It is an arithmetic number, because the mean of its divisors is an integer number (69890619909).

Almost surely, 2^139781239817 is an apocalyptic number.

It is an amenable number.

139781239817 is a deficient number, since it is larger than the sum of its proper divisors (1).

139781239817 is an equidigital number, since it uses as much as digits as its factorization.

139781239817 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4572288, while the sum is 59.

The spelling of 139781239817 in words is "one hundred thirty-nine billion, seven hundred eighty-one million, two hundred thirty-nine thousand, eight hundred seventeen".