138588661 has 2 divisors, whose sum is σ = 138588662. Its totient is φ = 138588660.

The previous prime is 138588601. The next prime is 138588701. The reversal of 138588661 is 166885831.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 77264100 + 61324561 = 8790^2 + 7831^2 .

It is a cyclic number.

It is not a de Polignac number, because 138588661 - 2⁷ = 138588533 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (138588601) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69294330 + 69294331.

It is an arithmetic number, because the mean of its divisors is an integer number (69294331).

Almost surely, 2^138588661 is an apocalyptic number.

It is an amenable number.

138588661 is a deficient number, since it is larger than the sum of its proper divisors (1).

138588661 is an equidigital number, since it uses as much as digits as its factorization.

138588661 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 276480, while the sum is 46.

The square root of 138588661 is about 11772.3685382339. The cubic root of 138588661 is about 517.4986639872.

The spelling of 138588661 in words is "one hundred thirty-eight million, five hundred eighty-eight thousand, six hundred sixty-one".