138647813 has 2 divisors, whose sum is σ = 138647814. Its totient is φ = 138647812.

The previous prime is 138647809. The next prime is 138647833. The reversal of 138647813 is 318746831.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 115627009 + 23020804 = 10753^2 + 4798^2 .

It is a cyclic number.

It is not a de Polignac number, because 138647813 - 2² = 138647809 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (138647833) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69323906 + 69323907.

It is an arithmetic number, because the mean of its divisors is an integer number (69323907).

Almost surely, 2^138647813 is an apocalyptic number.

It is an amenable number.

138647813 is a deficient number, since it is larger than the sum of its proper divisors (1).

138647813 is an equidigital number, since it uses as much as digits as its factorization.

138647813 is an evil number, because the sum of its binary digits is even.

The product of its digits is 96768, while the sum is 41.

The square root of 138647813 is about 11774.8805938744. The cubic root of 138647813 is about 517.5722792615.

The spelling of 138647813 in words is "one hundred thirty-eight million, six hundred forty-seven thousand, eight hundred thirteen".