18806919793 has 4 divisors (see below), whose sum is σ = 18812207680. Its totient is φ = 18801631908.

The previous prime is 18806919757. The next prime is 18806919811. The reversal of 18806919793 is 39791960881.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 39791960881 = 70717 ⋅562693.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18806919793 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18806919743) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2638605 + ... + 2645722.

It is an arithmetic number, because the mean of its divisors is an integer number (4703051920).

Almost surely, 2^18806919793 is an apocalyptic number.

It is an amenable number.

18806919793 is a deficient number, since it is larger than the sum of its proper divisors (5287887).

18806919793 is an equidigital number, since it uses as much as digits as its factorization.

18806919793 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5287886.

The product of its (nonzero) digits is 5878656, while the sum is 61.

The spelling of 18806919793 in words is "eighteen billion, eight hundred six million, nine hundred nineteen thousand, seven hundred ninety-three".