138388669 has 2 divisors, whose sum is σ = 138388670. Its totient is φ = 138388668.

The previous prime is 138388651. The next prime is 138388697. The reversal of 138388669 is 966883831.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 131560900 + 6827769 = 11470^2 + 2613^2 .

It is a cyclic number.

It is not a de Polignac number, because 138388669 - 2¹⁹ = 137864381 is a prime.

It is a super-2 number, since 2×138388669² = 38302847415183122, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (138388699) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69194334 + 69194335.

It is an arithmetic number, because the mean of its divisors is an integer number (69194335).

Almost surely, 2^138388669 is an apocalyptic number.

It is an amenable number.

138388669 is a deficient number, since it is larger than the sum of its proper divisors (1).

138388669 is an equidigital number, since it uses as much as digits as its factorization.

138388669 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1492992, while the sum is 52.

The square root of 138388669 is about 11763.8713440772. The cubic root of 138388669 is about 517.2496166372.

The spelling of 138388669 in words is "one hundred thirty-eight million, three hundred eighty-eight thousand, six hundred sixty-nine".