138861517 has 4 divisors (see below), whose sum is σ = 138904416. Its totient is φ = 138818620.

The previous prime is 138861509. The next prime is 138861523. The reversal of 138861517 is 715168831.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 138861517 - 2³ = 138861509 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

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 138861517.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138561517) 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, 16159 + ... + 23212.

It is an arithmetic number, because the mean of its divisors is an integer number (34726104).

Almost surely, 2^138861517 is an apocalyptic number.

It is an amenable number.

138861517 is a deficient number, since it is larger than the sum of its proper divisors (42899).

138861517 is an equidigital number, since it uses as much as digits as its factorization.

138861517 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42898.

The product of its digits is 40320, while the sum is 40.

The square root of 138861517 is about 11783.9516716592. The cubic root of 138861517 is about 517.8380617614.

The spelling of 138861517 in words is "one hundred thirty-eight million, eight hundred sixty-one thousand, five hundred seventeen".