138775509 has 12 divisors (see below), whose sum is σ = 200911776. Its totient is φ = 92305512.

The previous prime is 138775477. The next prime is 138775517. The reversal of 138775509 is 905577831.

138775509 is a `hidden beast` number, since 13 + 87 + 7 + 550 + 9 = 666.

It is not a de Polignac number, because 138775509 - 2⁵ = 138775477 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138775519) by changing a digit.

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 11 ways as a sum of consecutive naturals, for example, 13417 + ... + 21390.

It is an arithmetic number, because the mean of its divisors is an integer number (16742648).

Almost surely, 2^138775509 is an apocalyptic number.

It is an amenable number.

138775509 is a deficient number, since it is larger than the sum of its proper divisors (62136267).

138775509 is a wasteful number, since it uses less digits than its factorization.

138775509 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 35256 (or 35253 counting only the distinct ones).

The product of its (nonzero) digits is 264600, while the sum is 45.

The square root of 138775509 is about 11780.3017363733. The cubic root of 138775509 is about 517.7311268920.

The spelling of 138775509 in words is "one hundred thirty-eight million, seven hundred seventy-five thousand, five hundred nine".