138656565 has 24 divisors (see below), whose sum is σ = 243636120. Its totient is φ = 72935424.

The previous prime is 138656519. The next prime is 138656587. The reversal of 138656565 is 565656831.

138656565 is a `hidden beast` number, since 1 + 3 + 86 + 5 + 6 + 565 = 666.

138656565 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 33942276 + 104714289 = 5826^2 + 10233^2 .

It is not a de Polignac number, because 138656565 - 2¹³ = 138648373 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 138656565.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 17820 + ... + 24389.

It is an arithmetic number, because the mean of its divisors is an integer number (10151505).

Almost surely, 2^138656565 is an apocalyptic number.

138656565 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

138656565 is a deficient number, since it is larger than the sum of its proper divisors (104979555).

138656565 is a wasteful number, since it uses less digits than its factorization.

138656565 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 42293 (or 42290 counting only the distinct ones).

The product of its digits is 648000, while the sum is 45.

The square root of 138656565 is about 11775.2522265980. The cubic root of 138656565 is about 517.5831694375.

The spelling of 138656565 in words is "one hundred thirty-eight million, six hundred fifty-six thousand, five hundred sixty-five".