138617247 has 4 divisors (see below), whose sum is σ = 184823000. Its totient is φ = 92411496.

The previous prime is 138617239. The next prime is 138617249. The reversal of 138617247 is 742716831.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 742716831 = 3 ⋅247572277.

It is not a de Polignac number, because 138617247 - 2³ = 138617239 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138617249) 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, 23102872 + ... + 23102877.

It is an arithmetic number, because the mean of its divisors is an integer number (46205750).

Almost surely, 2^138617247 is an apocalyptic number.

138617247 is a deficient number, since it is larger than the sum of its proper divisors (46205753).

138617247 is an equidigital number, since it uses as much as digits as its factorization.

138617247 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 46205752.

The product of its digits is 56448, while the sum is 39.

The square root of 138617247 is about 11773.5825898492. The cubic root of 138617247 is about 517.5342421740.

The spelling of 138617247 in words is "one hundred thirty-eight million, six hundred seventeen thousand, two hundred forty-seven".