138917 has 2 divisors, whose sum is σ = 138918. Its totient is φ = 138916.

The previous prime is 138899. The next prime is 138923. The reversal of 138917 is 719831.

138917 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 81796 + 57121 = 286^2 + 239^2 .

It is a cyclic number.

It is not a de Polignac number, because 138917 - 2⁸ = 138661 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 138917.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (138937) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69458 + 69459.

It is an arithmetic number, because the mean of its divisors is an integer number (69459).

2¹³⁸⁹¹⁷ is an apocalyptic number.

It is an amenable number.

138917 is a deficient number, since it is larger than the sum of its proper divisors (1).

138917 is an equidigital number, since it uses as much as digits as its factorization.

138917 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1512, while the sum is 29.

The square root of 138917 is about 372.7157093550. The cubic root of 138917 is about 51.7907021072.

It can be divided in two parts, 13 and 8917, that multiplied together give a triangular number (115921 = T₄₈₁).

The spelling of 138917 in words is "one hundred thirty-eight thousand, nine hundred seventeen".