138444769 has 2 divisors, whose sum is σ = 138444770. Its totient is φ = 138444768.

The previous prime is 138444767. The next prime is 138444793. The reversal of 138444769 is 967444831.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 90003169 + 48441600 = 9487^2 + 6960^2 .

It is a cyclic number.

It is not a de Polignac number, because 138444769 - 2¹ = 138444767 is a prime.

It is a super-2 number, since 2×138444769² = 38333908126926722, which contains 22 as substring.

Together with 138444767, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (138444767) 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, 69222384 + 69222385.

It is an arithmetic number, because the mean of its divisors is an integer number (69222385).

Almost surely, 2^138444769 is an apocalyptic number.

It is an amenable number.

138444769 is a deficient number, since it is larger than the sum of its proper divisors (1).

138444769 is an equidigital number, since it uses as much as digits as its factorization.

138444769 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 580608, while the sum is 46.

The square root of 138444769 is about 11766.2555216177. The cubic root of 138444769 is about 517.3195014130.

The spelling of 138444769 in words is "one hundred thirty-eight million, four hundred forty-four thousand, seven hundred sixty-nine".