138864917 has 2 divisors, whose sum is σ = 138864918. Its totient is φ = 138864916.

The previous prime is 138864911. The next prime is 138864941. The reversal of 138864917 is 719468831.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 134699236 + 4165681 = 11606^2 + 2041^2 .

It is a cyclic number.

It is not a de Polignac number, because 138864917 - 2¹⁴ = 138848533 is a prime.

It is a super-3 number, since 3×138864917³ (a number of 25 digits) contains 333 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (138864911) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69432458 + 69432459.

It is an arithmetic number, because the mean of its divisors is an integer number (69432459).

Almost surely, 2^138864917 is an apocalyptic number.

It is an amenable number.

138864917 is a deficient number, since it is larger than the sum of its proper divisors (1).

138864917 is an equidigital number, since it uses as much as digits as its factorization.

138864917 is an evil number, because the sum of its binary digits is even.

The product of its digits is 290304, while the sum is 47.

The square root of 138864917 is about 11784.0959347758. The cubic root of 138864917 is about 517.8422881184.

The spelling of 138864917 in words is "one hundred thirty-eight million, eight hundred sixty-four thousand, nine hundred seventeen".