18634378879 has 4 divisors (see below), whose sum is σ = 18635747760. Its totient is φ = 18633010000.

The previous prime is 18634378871. The next prime is 18634378883. The reversal of 18634378879 is 97887343681.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 97887343681 = 97 ⋅1009147873.

It is a cyclic number.

It is not a de Polignac number, because 18634378879 - 2³ = 18634378871 is a prime.

It is a super-2 number, since 2×18634378879² (a number of 21 digits) 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 18634378879.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18634378871) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 663814 + ... + 691315.

It is an arithmetic number, because the mean of its divisors is an integer number (4658936940).

Almost surely, 2^18634378879 is an apocalyptic number.

18634378879 is a deficient number, since it is larger than the sum of its proper divisors (1368881).

18634378879 is a wasteful number, since it uses less digits than its factorization.

18634378879 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1368880.

The product of its digits is 48771072, while the sum is 64.

The spelling of 18634378879 in words is "eighteen billion, six hundred thirty-four million, three hundred seventy-eight thousand, eight hundred seventy-nine".