138228817 has 4 divisors (see below), whose sum is σ = 138728116. Its totient is φ = 137729520.

The previous prime is 138228787. The next prime is 138228821. The reversal of 138228817 is 718822831.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 22429696 + 115799121 = 4736^2 + 10761^2 .

It is a cyclic number.

It is not a de Polignac number, because 138228817 - 2¹¹ = 138226769 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 138228817.

It is not an unprimeable number, because it can be changed into a prime (138228017) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 249234 + ... + 249787.

It is an arithmetic number, because the mean of its divisors is an integer number (34682029).

Almost surely, 2^138228817 is an apocalyptic number.

It is an amenable number.

138228817 is a deficient number, since it is larger than the sum of its proper divisors (499299).

138228817 is an equidigital number, since it uses as much as digits as its factorization.

138228817 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 499298.

The product of its digits is 43008, while the sum is 40.

The square root of 138228817 is about 11757.0751890085. The cubic root of 138228817 is about 517.0503824984.

The spelling of 138228817 in words is "one hundred thirty-eight million, two hundred twenty-eight thousand, eight hundred seventeen".