138775679 has 4 divisors (see below), whose sum is σ = 158600784. Its totient is φ = 118950576.

The previous prime is 138775667. The next prime is 138775723. The reversal of 138775679 is 976577831.

138775679 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 138775679 - 2²⁰ = 137727103 is a prime.

It is a super-2 number, since 2×138775679² = 38517378163822082, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 138775679.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (138775619) 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, 9912542 + ... + 9912555.

It is an arithmetic number, because the mean of its divisors is an integer number (39650196).

Almost surely, 2^138775679 is an apocalyptic number.

138775679 is a deficient number, since it is larger than the sum of its proper divisors (19825105).

138775679 is an equidigital number, since it uses as much as digits as its factorization.

138775679 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19825104.

The product of its digits is 2222640, while the sum is 53.

The square root of 138775679 is about 11780.3089518060. The cubic root of 138775679 is about 517.7313382988.

The spelling of 138775679 in words is "one hundred thirty-eight million, seven hundred seventy-five thousand, six hundred seventy-nine".