138720307 has 8 divisors (see below), whose sum is σ = 153155520. Its totient is φ = 124589160.

The previous prime is 138720301. The next prime is 138720331. The reversal of 138720307 is 703027831.

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 138720307 - 2³ = 138720299 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (138720301) 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 7 ways as a sum of consecutive naturals, for example, 75057 + ... + 76882.

It is an arithmetic number, because the mean of its divisors is an integer number (19144440).

Almost surely, 2^138720307 is an apocalyptic number.

138720307 is a deficient number, since it is larger than the sum of its proper divisors (14435213).

138720307 is a wasteful number, since it uses less digits than its factorization.

138720307 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 152033.

The product of its (nonzero) digits is 7056, while the sum is 31.

The square root of 138720307 is about 11777.9585242944. The cubic root of 138720307 is about 517.6624702436.

The spelling of 138720307 in words is "one hundred thirty-eight million, seven hundred twenty thousand, three hundred seven".