138294721 has 8 divisors (see below), whose sum is σ = 139305600. Its totient is φ = 137287920.

The previous prime is 138294719. The next prime is 138294733. The reversal of 138294721 is 127492831.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 138294721 - 2¹ = 138294719 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (138294781) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 99451 + ... + 100831.

It is an arithmetic number, because the mean of its divisors is an integer number (17413200).

Almost surely, 2^138294721 is an apocalyptic number.

It is an amenable number.

138294721 is a deficient number, since it is larger than the sum of its proper divisors (1010879).

138294721 is a wasteful number, since it uses less digits than its factorization.

138294721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2039.

The product of its digits is 24192, while the sum is 37.

The square root of 138294721 is about 11759.8775929004. The cubic root of 138294721 is about 517.1325416195.

The spelling of 138294721 in words is "one hundred thirty-eight million, two hundred ninety-four thousand, seven hundred twenty-one".