138017765 has 4 divisors (see below), whose sum is σ = 165621324. Its totient is φ = 110414208.

The previous prime is 138017753. The next prime is 138017791. The reversal of 138017765 is 567710831.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 567710831 = 21851 ⋅25981.

It can be written as a sum of positive squares in 2 ways, for example, as 45819361 + 92198404 = 6769^2 + 9602^2 .

It is a cyclic number.

It is not a de Polignac number, because 138017765 - 2²² = 133823461 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 (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13801772 + ... + 13801781.

It is an arithmetic number, because the mean of its divisors is an integer number (41405331).

Almost surely, 2^138017765 is an apocalyptic number.

It is an amenable number.

138017765 is a deficient number, since it is larger than the sum of its proper divisors (27603559).

138017765 is an equidigital number, since it uses as much as digits as its factorization.

138017765 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27603558.

The product of its (nonzero) digits is 35280, while the sum is 38.

The square root of 138017765 is about 11748.0962287513. The cubic root of 138017765 is about 516.7870989924.

The spelling of 138017765 in words is "one hundred thirty-eight million, seventeen thousand, seven hundred sixty-five".