138779 has 4 divisors (see below), whose sum is σ = 140184. Its totient is φ = 137376.

The previous prime is 138763. The next prime is 138793. The reversal of 138779 is 977831.

138779 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 138779 - 2⁴ = 138763 is a prime.

It is a super-2 number, since 2×138779² = 38519221682, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (138739) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 542 + ... + 755.

It is an arithmetic number, because the mean of its divisors is an integer number (35046).

2¹³⁸⁷⁷⁹ is an apocalyptic number.

138779 is a deficient number, since it is larger than the sum of its proper divisors (1405).

138779 is a wasteful number, since it uses less digits than its factorization.

138779 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1404.

The product of its digits is 10584, while the sum is 35.

The square root of 138779 is about 372.5305356612. The cubic root of 138779 is about 51.7735468158.

The spelling of 138779 in words is "one hundred thirty-eight thousand, seven hundred seventy-nine".