138215117 has 6 divisors (see below), whose sum is σ = 146823978. Its totient is φ = 130084544.

The previous prime is 138215113. The next prime is 138215137. The reversal of 138215117 is 711512831.

It can be written as a sum of positive squares in 3 ways, for example, as 27102436 + 111112681 = 5206^2 + 10541^2 .

It is not a de Polignac number, because 138215117 - 2² = 138215113 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 138215117.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138215113) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 238838 + ... + 239415.

It is an arithmetic number, because the mean of its divisors is an integer number (24470663).

Almost surely, 2^138215117 is an apocalyptic number.

138215117 is a gapful number since it is divisible by the number (17) formed by its first and last digit.

It is an amenable number.

138215117 is a deficient number, since it is larger than the sum of its proper divisors (8608861).

138215117 is an equidigital number, since it uses as much as digits as its factorization.

138215117 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 478287 (or 478270 counting only the distinct ones).

The product of its digits is 1680, while the sum is 29.

The square root of 138215117 is about 11756.4925466739. The cubic root of 138215117 is about 517.0333001359.

Adding to 138215117 its reverse (711512831), we get a palindrome (849727948).

The spelling of 138215117 in words is "one hundred thirty-eight million, two hundred fifteen thousand, one hundred seventeen".