18155644679 has 4 divisors (see below), whose sum is σ = 18260590776. Its totient is φ = 18050698584.

The previous prime is 18155644651. The next prime is 18155644697. The reversal of 18155644679 is 97644655181.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18155644679 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18155644699) 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, 52472789 + ... + 52473134.

It is an arithmetic number, because the mean of its divisors is an integer number (4565147694).

Almost surely, 2^18155644679 is an apocalyptic number.

18155644679 is a deficient number, since it is larger than the sum of its proper divisors (104946097).

18155644679 is a wasteful number, since it uses less digits than its factorization.

18155644679 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 104946096.

The product of its digits is 7257600, while the sum is 56.

The spelling of 18155644679 in words is "eighteen billion, one hundred fifty-five million, six hundred forty-four thousand, six hundred seventy-nine".