18556023213 has 64 divisors (see below), whose sum is σ = 34101329920. Its totient is φ = 9710559936.

The previous prime is 18556023203. The next prime is 18556023247. The reversal of 18556023213 is 31232065581.

18556023213 is a `hidden beast` number, since 1 + 8 + 5 + 5 + 602 + 32 + 13 = 666.

It is not a de Polignac number, because 18556023213 - 2¹² = 18556019117 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18556023203) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 282306 + ... + 341772.

It is an arithmetic number, because the mean of its divisors is an integer number (532833280).

Almost surely, 2^18556023213 is an apocalyptic number.

18556023213 is a gapful number since it is divisible by the number (13) formed by its first and last digit.

It is an amenable number.

18556023213 is a deficient number, since it is larger than the sum of its proper divisors (15545306707).

18556023213 is a wasteful number, since it uses less digits than its factorization.

18556023213 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 59623 (or 59617 counting only the distinct ones).

The product of its (nonzero) digits is 43200, while the sum is 36.

Adding to 18556023213 its reverse (31232065581), we get a palindrome (49788088794).

The spelling of 18556023213 in words is "eighteen billion, five hundred fifty-six million, twenty-three thousand, two hundred thirteen".