138778317 has 18 divisors (see below), whose sum is σ = 205488426. Its totient is φ = 90252480.

The previous prime is 138778307. The next prime is 138778319. The reversal of 138778317 is 713877831.

It can be written as a sum of positive squares in 3 ways, for example, as 29909961 + 108868356 = 5469^2 + 10434^2 .

It is not a de Polignac number, because 138778317 - 2⁴ = 138778301 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138778319) 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 in 17 ways as a sum of consecutive naturals, for example, 10543 + ... + 19715.

Almost surely, 2^138778317 is an apocalyptic number.

It is an amenable number.

138778317 is a deficient number, since it is larger than the sum of its proper divisors (66710109).

138778317 is an equidigital number, since it uses as much as digits as its factorization.

138778317 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9261 (or 9217 counting only the distinct ones).

The product of its digits is 197568, while the sum is 45.

The square root of 138778317 is about 11780.4209177771. The cubic root of 138778317 is about 517.7346188127.

The spelling of 138778317 in words is "one hundred thirty-eight million, seven hundred seventy-eight thousand, three hundred seventeen".