138642775 has 12 divisors (see below), whose sum is σ = 173016952. Its totient is φ = 110204640.

The previous prime is 138642773. The next prime is 138642821. The reversal of 138642775 is 577246831.

It is not a de Polignac number, because 138642775 - 2¹ = 138642773 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 (138642773) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 13737 + ... + 21586.

Almost surely, 2^138642775 is an apocalyptic number.

138642775 is a deficient number, since it is larger than the sum of its proper divisors (34374177).

138642775 is a wasteful number, since it uses less digits than its factorization.

138642775 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35490 (or 35485 counting only the distinct ones).

The product of its digits is 282240, while the sum is 43.

The square root of 138642775 is about 11774.6666619484. Note that the first 5 decimals coincide. The cubic root of 138642775 is about 517.5660102343.

The spelling of 138642775 in words is "one hundred thirty-eight million, six hundred forty-two thousand, seven hundred seventy-five".