138706445 has 18 divisors (see below), whose sum is σ = 174762378. Its totient is φ = 105677088.

The previous prime is 138706439. The next prime is 138706453. The reversal of 138706445 is 544607831.

It can be written as a sum of positive squares in 3 ways, for example, as 77193796 + 61512649 = 8786^2 + 7843^2 .

It is not a de Polignac number, because 138706445 - 2⁴ = 138706429 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 138706399 and 138706408.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 605591 + ... + 605819.

It is an arithmetic number, because the mean of its divisors is an integer number (9709021).

Almost surely, 2^138706445 is an apocalyptic number.

It is an amenable number.

138706445 is a deficient number, since it is larger than the sum of its proper divisors (36055933).

138706445 is an frugal number, since it uses more digits than its factorization.

138706445 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 509 (or 257 counting only the distinct ones).

The product of its (nonzero) digits is 80640, while the sum is 38.

The square root of 138706445 is about 11777.3700374914. The cubic root of 138706445 is about 517.6452267307.

The spelling of 138706445 in words is "one hundred thirty-eight million, seven hundred six thousand, four hundred forty-five".