138450709 has 4 divisors (see below), whose sum is σ = 138491820. Its totient is φ = 138409600.

The previous prime is 138450677. The next prime is 138450751. The reversal of 138450709 is 907054831.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 907054831 = 9587 ⋅94613.

It can be written as a sum of positive squares in 2 ways, for example, as 21594609 + 116856100 = 4647^2 + 10810^2 .

It is a cyclic number.

It is not a de Polignac number, because 138450709 - 2⁵ = 138450677 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138450779) 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, 15004 + ... + 22405.

It is an arithmetic number, because the mean of its divisors is an integer number (34622955).

Almost surely, 2^138450709 is an apocalyptic number.

It is an amenable number.

138450709 is a deficient number, since it is larger than the sum of its proper divisors (41111).

138450709 is an equidigital number, since it uses as much as digits as its factorization.

138450709 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41110.

The product of its (nonzero) digits is 30240, while the sum is 37.

The square root of 138450709 is about 11766.5079356621. The cubic root of 138450709 is about 517.3268998721.

The spelling of 138450709 in words is "one hundred thirty-eight million, four hundred fifty thousand, seven hundred nine".