138684859 has 4 divisors (see below), whose sum is σ = 138709816. Its totient is φ = 138659904.

The previous prime is 138684839. The next prime is 138684883. The reversal of 138684859 is 958486831.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 958486831 = 379 ⋅2528989.

It is a cyclic number.

It is not a de Polignac number, because 138684859 - 2⁹ = 138684347 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (138684829) 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, 52 + ... + 16654.

It is an arithmetic number, because the mean of its divisors is an integer number (34677454).

Almost surely, 2^138684859 is an apocalyptic number.

138684859 is a deficient number, since it is larger than the sum of its proper divisors (24957).

138684859 is an equidigital number, since it uses as much as digits as its factorization.

138684859 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24956.

The product of its digits is 1658880, while the sum is 52.

The square root of 138684859 is about 11776.4535833162. The cubic root of 138684859 is about 517.6183727285.

The spelling of 138684859 in words is "one hundred thirty-eight million, six hundred eighty-four thousand, eight hundred fifty-nine".