18221557233 has 32 divisors (see below), whose sum is σ = 26963131392. Its totient is φ = 10852430400.

The previous prime is 18221557199. The next prime is 18221557259. The reversal of 18221557233 is 33275512281.

It is not a de Polignac number, because 18221557233 - 2⁶ = 18221557169 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 18221557191 and 18221557200.

It is not an unprimeable number, because it can be changed into a prime (18221507233) 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 31 ways as a sum of consecutive naturals, for example, 2619466 + ... + 2626412.

It is an arithmetic number, because the mean of its divisors is an integer number (842597856).

Almost surely, 2^18221557233 is an apocalyptic number.

It is an amenable number.

18221557233 is a deficient number, since it is larger than the sum of its proper divisors (8741574159).

18221557233 is a wasteful number, since it uses less digits than its factorization.

18221557233 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8325.

The product of its digits is 100800, while the sum is 39.

The spelling of 18221557233 in words is "eighteen billion, two hundred twenty-one million, five hundred fifty-seven thousand, two hundred thirty-three".