18272821843 has 4 divisors (see below), whose sum is σ = 18294244528. Its totient is φ = 18251399160.

The previous prime is 18272821829. The next prime is 18272821859. The reversal of 18272821843 is 34812827281.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 34812827281 = 71 ⋅490321511.

It is a cyclic number.

It is not a de Polignac number, because 18272821843 - 2²⁹ = 17735950931 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 18272821793 and 18272821802.

It is not an unprimeable number, because it can be changed into a prime (18272821883) 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, 10710063 + ... + 10711768.

It is an arithmetic number, because the mean of its divisors is an integer number (4573561132).

Almost surely, 2^18272821843 is an apocalyptic number.

18272821843 is a deficient number, since it is larger than the sum of its proper divisors (21422685).

18272821843 is an equidigital number, since it uses as much as digits as its factorization.

18272821843 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21422684.

The product of its digits is 344064, while the sum is 46.

The spelling of 18272821843 in words is "eighteen billion, two hundred seventy-two million, eight hundred twenty-one thousand, eight hundred forty-three".