139666717 has 2 divisors, whose sum is σ = 139666718. Its totient is φ = 139666716.

The previous prime is 139666699. The next prime is 139666733. The reversal of 139666717 is 717666931.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 108597241 + 31069476 = 10421^2 + 5574^2 .

It is an emirp because it is prime and its reverse (717666931) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 139666717 - 2⁷ = 139666589 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (139676717) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69833358 + 69833359.

It is an arithmetic number, because the mean of its divisors is an integer number (69833359).

Almost surely, 2^139666717 is an apocalyptic number.

It is an amenable number.

139666717 is a deficient number, since it is larger than the sum of its proper divisors (1).

139666717 is an equidigital number, since it uses as much as digits as its factorization.

139666717 is an evil number, because the sum of its binary digits is even.

The product of its digits is 285768, while the sum is 46.

The square root of 139666717 is about 11818.0673969985. The cubic root of 139666717 is about 518.8370423061.

The spelling of 139666717 in words is "one hundred thirty-nine million, six hundred sixty-six thousand, seven hundred seventeen".