139409917 has 2 divisors, whose sum is σ = 139409918. Its totient is φ = 139409916.

The previous prime is 139409899. The next prime is 139409927. The reversal of 139409917 is 719904931.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 87871876 + 51538041 = 9374^2 + 7179^2 .

It is a cyclic number.

It is not a de Polignac number, because 139409917 - 2⁷ = 139409789 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (139409927) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69704958 + 69704959.

It is an arithmetic number, because the mean of its divisors is an integer number (69704959).

Almost surely, 2^139409917 is an apocalyptic number.

It is an amenable number.

139409917 is a deficient number, since it is larger than the sum of its proper divisors (1).

139409917 is an equidigital number, since it uses as much as digits as its factorization.

139409917 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 61236, while the sum is 43.

The square root of 139409917 is about 11807.1976776880. The cubic root of 139409917 is about 518.5188584220.

The spelling of 139409917 in words is "one hundred thirty-nine million, four hundred nine thousand, nine hundred seventeen".