18993404823 has 8 divisors (see below), whose sum is σ = 25325357568. Its totient is φ = 12661860984.

The previous prime is 18993404789. The next prime is 18993404831. The reversal of 18993404823 is 32840439981.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 18993404823 - 2²⁰ = 18992356247 is a prime.

It is a super-2 number, since 2×18993404823² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18993404893) 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 7 ways as a sum of consecutive naturals, for example, 30940 + ... + 197342.

It is an arithmetic number, because the mean of its divisors is an integer number (3165669696).

Almost surely, 2^18993404823 is an apocalyptic number.

18993404823 is a deficient number, since it is larger than the sum of its proper divisors (6331952745).

18993404823 is a wasteful number, since it uses less digits than its factorization.

18993404823 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 204453.

The product of its (nonzero) digits is 1492992, while the sum is 51.

The spelling of 18993404823 in words is "eighteen billion, nine hundred ninety-three million, four hundred four thousand, eight hundred twenty-three".