138605725 has 24 divisors (see below), whose sum is σ = 176677928. Its totient is φ = 107827200.

The previous prime is 138605711. The next prime is 138605749. The reversal of 138605725 is 527506831.

It can be written as a sum of positive squares in 12 ways, for example, as 114340249 + 24265476 = 10693^2 + 4926^2 .

It is not a de Polignac number, because 138605725 - 2⁹ = 138605213 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

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 23 ways as a sum of consecutive naturals, for example, 147457 + ... + 148393.

Almost surely, 2^138605725 is an apocalyptic number.

It is an amenable number.

138605725 is a deficient number, since it is larger than the sum of its proper divisors (38072203).

138605725 is an equidigital number, since it uses as much as digits as its factorization.

138605725 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1105 (or 1100 counting only the distinct ones).

The product of its (nonzero) digits is 50400, while the sum is 37.

The square root of 138605725 is about 11773.0932638793. The cubic root of 138605725 is about 517.5199024606.

The spelling of 138605725 in words is "one hundred thirty-eight million, six hundred five thousand, seven hundred twenty-five".