138506271 has 4 divisors (see below), whose sum is σ = 184675032. Its totient is φ = 92337512.

The previous prime is 138506243. The next prime is 138506273. The reversal of 138506271 is 172605831.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 172605831 = 3 ⋅57535277.

It is a cyclic number.

It is not a de Polignac number, because 138506271 - 2²² = 134311967 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138506273) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 23084376 + ... + 23084381.

It is an arithmetic number, because the mean of its divisors is an integer number (46168758).

Almost surely, 2^138506271 is an apocalyptic number.

138506271 is a deficient number, since it is larger than the sum of its proper divisors (46168761).

138506271 is an equidigital number, since it uses as much as digits as its factorization.

138506271 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 46168760.

The product of its (nonzero) digits is 10080, while the sum is 33.

The square root of 138506271 is about 11768.8687221840. The cubic root of 138506271 is about 517.3960938671.

The spelling of 138506271 in words is "one hundred thirty-eight million, five hundred six thousand, two hundred seventy-one".