138940723 has 4 divisors (see below), whose sum is σ = 144981648. Its totient is φ = 132899800.

The previous prime is 138940721. The next prime is 138940771. The reversal of 138940723 is 327049831.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 327049831 = 19 ⋅17213149.

It is a cyclic number.

It is not a de Polignac number, because 138940723 - 2¹ = 138940721 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (138940721) 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, 3020428 + ... + 3020473.

It is an arithmetic number, because the mean of its divisors is an integer number (36245412).

Almost surely, 2^138940723 is an apocalyptic number.

138940723 is a deficient number, since it is larger than the sum of its proper divisors (6040925).

138940723 is an equidigital number, since it uses as much as digits as its factorization.

138940723 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6040924.

The product of its (nonzero) digits is 36288, while the sum is 37.

The square root of 138940723 is about 11787.3119497195. The cubic root of 138940723 is about 517.9365005668.

The spelling of 138940723 in words is "one hundred thirty-eight million, nine hundred forty thousand, seven hundred twenty-three".