138487273 has 4 divisors (see below), whose sum is σ = 138516948. Its totient is φ = 138457600.

The previous prime is 138487259. The next prime is 138487289. The reversal of 138487273 is 372784831.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 372784831 = 661 ⋅563971.

It can be written as a sum of positive squares in 2 ways, for example, as 84860944 + 53626329 = 9212^2 + 7323^2 .

It is a cyclic number.

It is not a de Polignac number, because 138487273 - 2⁵ = 138487241 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (138487213) 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, 6136 + ... + 17737.

It is an arithmetic number, because the mean of its divisors is an integer number (34629237).

Almost surely, 2^138487273 is an apocalyptic number.

It is an amenable number.

138487273 is a deficient number, since it is larger than the sum of its proper divisors (29675).

138487273 is an equidigital number, since it uses as much as digits as its factorization.

138487273 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 29674.

The product of its digits is 225792, while the sum is 43.

The square root of 138487273 is about 11768.0615651007. The cubic root of 138487273 is about 517.3724368385.

The spelling of 138487273 in words is "one hundred thirty-eight million, four hundred eighty-seven thousand, two hundred seventy-three".